Creating An Effects Loop For Code25 / Code50 Using Multiple Amps.

Discussion in 'Marshall Amps' started by dpaterson, Sep 22, 2018.

  1. dpaterson

    dpaterson Member

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    Hello all.

    I'm willing to bet the title of thread has caught the attention of some folks!!! LOL!!! But nope. Sorry. It's not what you think it is!!!

    And before I begin (and so that nobody tries to spoil my day): I visit these (and other Marshall related) forums often enough and my beloved CODE amps. (I have FIVE of them) seem to get a bad rap. No idea why. Maybe I'm just lucky i.e. I've never had a single issue with any of my amps. whatsoever. And I don't know if it's a combo. of my guitars (pickups) and wireless systems and PA or because of the way I use these amps. but I get truly MONSTER sound out of them. And I have indeed owned Marshall valve heads and stacks on occasion over the years so I do know the difference. And if I can be of any assistance to CODE owners: am too happy to be (actually provide some unofficial support for them on Marshall's own forums) (but the reason I'm posting this here is because I posted it over there yesterday and no input from anyone i.e. those forums are usually very quiet save for the continuous repetitive posts by owners who couldn't be bothered to help themselves of course).

    Right. Now that we have all of the above out of the way!!! LOL!!!

    As you all know: there's no effects loop on the CODE25 and CODE50. I've not found this to be an issue but I would like to try and hook up an equalizer (Boss GE-7) to try out. I've have tried putting the pedal in the front but with high gain amps. like the JCM800 the noise levels lift WAY too much especially if you're using PRE FX like distortion (and REVERB and DELAY make the situation worse). In addition to this there are certain pedals that just should be in an effects loop and not in front e.g. TC Electronic's MIMIQ (in front this pedal also raises the noise badly and quite frankly I think it's a joke but this is a whole other discussion which I'm happy to have) (but this being said: will give it the benefit of the doubt until I can try it in an effects loop assuming I can accomplish the below).

    So here's my plan (which requires two amps.):

    1 - Guitar straight into amp. 1 (say a CODE25).

    2 - On amp. 1: ONLY PRE FX and PRE AMP are turned ON i.e. everything else is turned OFF.

    3 - From amp. 1: take the LINE OUT (HEADPHONE) to a REAMP box (this to reduce the output level from amp. 1 from a line level signal back to an instrument level signal) (and this so as not to blow up your pedals or second amp.).

    4 - From the REAMP box: to pedal (or pedals i.e. however many you want in your "loop").

    5 - From pedals: into amp. 2 (another CODE25 for example) and on amp. 2 PRE FX and PRE AMP are turned OFF and everything else is turned ON.

    Can anybody think of any reason why this would NOT work???

    It IS INDEED an effects loop i.e. your effects are now sitting between the ouput stage of a PRE AMP (amp.1) and the input stage of a POWER AMP (amp. 2) which is indeed a normal effects loop as we all know it (this just being a very long winded way of accomplishing the same thing).

    Yeh. I know. I could just try it but I'd rather get some outside input before I go blasting my amps. because there's something I've not thought of here. Oh and don't worry: I won't hold anybody responsible if things go wrong!!!

    Regards,

    Dale (aka "Mr CODE"!!! LOL!!!).

    P.S.

    If Marshall would be so kind and forthcoming so as to give us a clue as to where the effects loops connections are on the CODE100/100H??? I've a feeling that a "proper" effects loop could very easily be "installed" on a CODE25/CODE50 IF you know where to splice into the internal connections!!! I say this because bear in mind that ALL of the CODE range use the same firmware and the front panels on the CODE50 and CODE100/100H are pretty much identical. And I also believe there is already a clue in the sense that on the CODE100/100H: the LINE OUT (HEADPHONE) socket disables the effects loop. Hmmmnnn... Unfortunately I don't have access to a CODE100/100H (at least not the type of access that will allow me near one with a screwdriver in hand!!! LOL!!!).
     
    Last edited: Sep 22, 2018
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  2. Clifdawg

    Clifdawg Active Member

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    I don't see why this wouldn't work from a technical standpoint, but the issue I see is that the second amp, even with the "preamp" turned off, is still giving you preamp sounds, since the "power amp" section is a digital recreation of power amp distortion in the preamp section. I just don't know if the effects would really come out that clear, if I'm honest.

    It's a rather convoluted setup, but hey, if it works for you, then go for it.
     
  3. Jethro Rocker

    Jethro Rocker Well-Known Member

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    I agree. Even with pre amp type turned off the signal still has to run through the circuitry to get to the power section. A Code really isn't the same as a tube amp with a dedicated effects loop. I think you'd be in the same boat. But try it.
    It IS rather convoluted but I can't see you hurting a digital amp in any way shape or form doing this.
     
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  4. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    On the last amp in line make sure you set it neutral (clean no dirt, reverb,cab sims,amp sims) and experimenting is a boat load of fun,:band: I used to do the line out thing on a cd 15 to a front man, lol by spreading out it gave me a larger sound, was not trying to get a efx loop though:cheers:
     
  5. dpaterson

    dpaterson Member

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    Good morning.

    Thank you very much for the replies. Really every much appreciated. A "thumbs up" from three members who, between them, have a post count of over 7 000. That's good enough for me!!! LOL!!!

    ---
    and
    Here I'm hoping that the AUDIO signal from the PRE AMP (first amp.) is enough to drive (and fool) the second amp.
    ---

    ---
    My thinking was to use "dirt" and the PRE AMP on the first amp. then use the POWER AMP (amp. sim.), cab. sim., and reverb and delay on the second amp.??? In other words (and the whole idea): I'm needing to EQ the output of the PRE AMP (after "dirt" and gain) (and then use reverb and delay post PRE AMP and pre POWER AMP) (but in just reading your post again this is quite possibly exactly what you are indeed saying). And as luck would have it: the modular design of the CODE (at least insofar as it's detailed by Marshall) allows for this very order of things. Matter of fact (and assuming the documentation is correct): MODULATION, REVERB, and DELAY are sitting in an "internal effects loop" so far as I can tell.
    ---

    Anyways: I didn't detail the ENTIRE setup so as to keep things simple for the sake of explanation. But believe it or not: a whole lot of thought went into this (and if it works it opens up a whole new world of possibilities that are not even possible with the CODE100/CODE100H in spite of their having an actual effects loop) (as noted below).

    Truth be told I need to hook up the following:
    Guitar -->> MXR Dyna Comp. -->> BOSS SD-1 -->> CODE JCM800 Emulation (NO CODE PRE FX) -->> BOSS GE-7 then into two (stereo) CODE Delays and CODE Reverbs -->> CODE Power Amps. -->> CODE Cabs.

    At any given time I'm running these things in stereo and each amp. is micd. up to go through an Alto PA. Depending on the application I'm using either two CODE25's or two CODE50's (and have a "spare" CODE25 that's used standalone for practice) (and to appease the household and the neighbours!!! LOL!!!). I've considered getting two CODE100's but a) it would be a total overkill (even with the Alto rated at a combined 2350W RMS the two CODE50's at full tilt, no mics., easily overpower it) and b) believe it or not two CODE100's (with built in and proper effects loops) wouldn't solve my problem i.e. I'd be going into two CODE100's and would then have to somehow combine the two effects loop outs to go into a mono pedal and then split again after the pedal to go back into each amp. (just as "convoluted"!!! LOL!!!). Could solve the problem with two EQ pedals of course but this would be a pain to use in practice (live) (and I've already had to "manufacture" my own footswitch for these things so that I can switch two amps. simultaneously with one footswitch) (this thanks to Marshall for going out of their way to ensure that this was NOT possible with the CODE range) and, of course, any of these scenarios would involve a whole bunch of extra cable in the signal chain. And I guess (assuming my little "plan" works of course) and if you really think about it: I'm just using a CODE25 as a "pedal" or "effect" in what would otherwise be a normal signal chain.

    I have to admit that it does "pain" me that these things don't have an effects loop like the CODE100/CODE100H. I say this because many are not as fortunate (or as dumb maybe???) to have "spare" CODE amps. lying around and need an effects loop. And I do believe that this was an executive / marketing decision as opposed to design. And I'm still pretty sure that it's a simple matter of knowing where to cut into the circuitry is all. And it may be even simpler than one thinks because, as I said, the "clue" lies in the fact that the line out/headphone socket on the CODE100/CODE100H disables the effects loop (my guess being that the effects loop starts with the line out / headphone signal but where to "back in" is the question). All of these amps. use the same firmware and the panels of the CODE50 and CODE100/CODE100H are identical. Go figure. (So if anybody feels like opening up their CODE100/CODE100H and taking pics. of where the actual effects loop jacks are connected to: send them and I'll do the experiment!!!). (Did ask my dealer if I could open up a CODE100H on the floor and they said "sure: after you've paid for it!!! LOL!!!). But like I said: I love these amps. and have to say that if I did have a gripe about them then this would be it. Other than (possibly) this: they're great and stick "you-know-what" into any amp. sim. (and it pains me to be able to say that I have most of them given my investment in them i.e. my investment in my "CODE amp. hoard" is about one tenth of that in amp. sims. but sounds one hundred times better).

    Anyways. Thanks. Nothing else to add at this point other than to say "well here goes ..." and "wish me luck"!!! LOL!!! Will report back!!! LOL!!!

    Thank again.

    Regards,

    Dale.

    P.S.

    As I said: a whole lot of thought went into this!!! LOL!!!

    CODEman.JPG

    ELres.jpg
     
    Last edited: Sep 24, 2018
  6. dpaterson

    dpaterson Member

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    Well good morning.

    You want the good news or the good news???

    I'm so happy I could just "you-know-what"!!! LOL!!!

    Works like an absolute charm!!!

    I can now select the JCM800 PRE AMP, turn the gain up as much as I like, EQ that sound in the "effects loop" with the BOSS GE-7, and hey presto: no additional noise. In other words: there is no additional noise generated other than what is normal for the JCM800 (it's a high gain amp. as all will know). One thing that I did forget to add in my initial posts: a lot of the noise is generated by the Distortion effect i.e. the combination of distortion and the JCM800 emulation with the EQ in front is actually the problem. But this solves anyway of course.

    There is just ONE thing that I got wrong (and I have NO idea how Herbert knew but well done Herbert and thanks for the instruction): I did indeed have to enable the PRE AMP section on amp. 2 (on the second amp.) and set it to "Natural (No FX)" for the simple reason that if you don't do this then the output of amp. 2 (the second amp.) is probably halved (approximately). Not quite sure what the reason for this could be??? It works perfectly and sounds great but is just softer is all. Whatever the reason though: this has the added benefit of giving you an extra set of (internal) EQ controls as well as an additional noise gate if required. I'm still experimenting but given this additional set of EQ controls I may not even need an EQ pedal. But whatever the case: this all works perfectly.

    Irony of ironies: as some may know the CODE range has a little quirk with the Master Volume control i.e. it's not linear in the sense that it's EXTREMELY sensitive between 0 and 1. Not really an issue with the CODE25 but with a CODE50 it's another story i.e. you go from "nothing (no sound)" to "live concert" in a heartbeat (and this can catch a person off guard sometimes especially if the volume of a particular preset is very high). (I used two CODE50's for this experiment by the way and not for any particular reason other than that they were already set up next to each other for a recording the other day). This little "configuration" "tames the beast" as it were.

    The only thing I would caution about: I would be careful to NOT enable the PRE FX on amp. 2 (on the second amp.). I say this because the PRE FX definitely adds gain (the Compressor and Distortion effects in particular). Not that this is something you'd want to do (it would be defeating the object in my case anyway). But I caution about this because I've a feeling that with all of this extra input going into amp. 2 (the second amp.) and then combine with even MORE gain from the PRE FX: I reckon there's a better than average chance of the speaker itself not being able to handle the output at full tilt. I could be wrong and I'm not going to try it to find out. But there it is.

    So there you have it. And I still have working amps.!!! LOL!!!

    Thanks again all for you input.

    Regards,

    Dale.
     
    Last edited: Sep 25, 2018
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  7. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    I am glad you were able to get it all as you liked, and I am glad that as I explained it worked for you! Cheers:cheers:
     
  8. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    Dpaterson! The only way I knew any of this, was by using the Marshall cd 15 line out into the instrument in of the fender front man ! The first time I tried it, I had the gain switch on, and it was terrible, gain switch off and it blossomed, with the little Marshall pushing it :agreed: and bye spreading them out gave me a larger sound :blah::cheers:
     
  9. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    I am now doing this with a pair of 40c’s and a lead 100 mosfet, with guitar going to a vox tone lab, 2 cables out of the vox into the instrument in’s on the 40c’s, efx loop send on 1 of the 40c’s to the instrument in on the mosfet, Sorry I tend to run my mouth a bit:cheers:,
     
  10. Mitchell Pearrow

    Mitchell Pearrow Well-Known Member

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    This is what all my blabbing sounds like at tv volume, all three amps and trying to cop a plexi tone! Cheers
     
  11. dpaterson

    dpaterson Member

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    Hello Herbert.

    Thanks for the posts and good wishes and input.

    Nice sound you got going there. Thanks for the clip. And nice to hear somebody talk of "spreading out for a large sound". I've spent a LONG time perfecting my "spread out large sound" with these amps. hence the amps. in stereo, micd. up, and the rest. It's not something that can be accomplished with plugins or pedals or anything else. Anyways. I digress. This is a WHOLE other thread for a WHOLE other day!!! LOL!!!

    Speaking of trying to "cop" a sound ALL of the above trouble was just to "cop" THIS sound:


    I got relatively close without my little "effects loop" but the CODE just cannot EQ those upper mids. on its own (and I had it on reasonable authority that's a JCM800 with a either a Boss SD-1 or Boss-GE7) (plus or minus whatever studio trickery e.g. EQ was involved of course) (and I have an issue with EQing my live sound when I'm recording it i.e. it's cheating!!! LOL!!!). So now I get it no problemo. Problem was (as noted I think): putting the SD-1 AND the GE-7 in front raised the noise level tremendously with the JCM800 and you would have to gate it so much that it choked the sound (and even then you could hear it over and above the sound anyway when you were playing).

    As far as my little "effects loop experiment" is concerned:

    It could be improved by adding a 1/4" (stereo) jack in parallel with the HEADPHONE / LINE OUT or simply replacing the 3.5mm (stereo) HEAPHONE / LINE OUT jack altogether. Those 3.5mm jacks are "iffy" at best as are the cables that are available to convert from 3.5mm (stereo) to 1/4" (stereo). I MAY get to this but before I do: I'm taking an amp. to an amp. builder (was supposed to do it this morning but got sidetracked) to see what would be involved in adding a "proper" effects loop to these amps. (the only reason being that although my little "plan" works like a charm it's HARDLY elegant let's face it!!! LOL!!!). If it IS possible and doable and I get it done I'll post details and pics. (I'm a bit tired of this "trade secret" thing with Marshall i.e. it would so easy for them to just say "well look for this on the board and there you go" but NO and believe me I have tried with them).

    Regards,

    Dale.

    P.S.
    I wouldn't worry about it!!! Have you seen MY posts (above)!!! LOL!!! And besides: always nice to share ideas and setups.
     
    Last edited: Sep 27, 2018
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  12. Antmax

    Antmax Well-Known Member

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    I bought a code on launch and have a bit of a love hate relationship. Still, I did keep it and have gotten two tube amps since. I found the CODE 50 has some weird EQ thing going on where treble and bass are always conflicting and I just can't get the right transition through the mids. One or the other goes wrong.

    I do use it as a preamp sometimes though. A really cool thing I got was one of those cheap ($30) powered 4 way headphone amps. it has 1x 1/4 TRS input and 4x 1/4 TRS outputs. I just use some cheap HOSA mono to stereo instrument cables.


    [​IMG] [​IMG]

    I have the lineout from the amp to the headphone out and can output to four devices with their own level knob and no discernable loss in quality. For some reason it sounds WAY better though my tube amps whether it's the DSL5c or 20HR and a Cab. With 4 outputs you can send one to your interface at the same time and potentially one for headphones.

    I can't help thinking that if Marshall had raised the price $50 and done some minor upgrades the CODE could have been so much better. Lots of potential.

    One thing I found is that buffered pedals can be hit or miss, sometimes they enhance the fizz and noisefloor, especially any falloff in sustain while you have the noisegate on.

    This thread has been an interesting read so I thought I'd share my own experiences.
     
    Last edited: Sep 27, 2018
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  13. dpaterson

    dpaterson Member

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    Hey Antmax.

    Thanks very much for the post, input, and pics.

    That's been my experience as well. This being said: overall I'm real happy. I have two presets of my own that I use most all of the time and (so far as I'm concerned anyway) the sound is as good as anything I've had with valves LIVE and I actually really love the sound. But when it comes to recording I notice this issue (more so with mics.).

    Agreed. I would gladly have paid more for a few things not least of which being an effects loop (and the CODE100/CODE100H had not been released when I bought my amps. and at the time it actually didn't look like it was EVER going to be released). One thing is for sure though (again: it's my opinion but based, I believe, my experiences to date): they still stick "you-know-what" into amp. sims. My investment in amp. sims. is WAY more than my investment in my five CODE amps. and not ONE has given me the same sound (and believe me when I say I've tried HARD mainly because I've kept saying to myself "there must be tens of thousands of people using this software so it must be you" but, for me anyway, they don't come close).

    I don't have many pedals. The few that I do have were sort of "purpose chosen". I have both buffered and true bypass and I've not found any difference at all. They all seem to cause an issue with noise but some worse than others. I cannot, for example, hook up my MXR Dynacomp and turn the sensitivity up anywhere past about 9 'o clock and the noise starts (even bought a Boss CS-3 because I thought it was just the Dynacomp making trouble but same thing). Overdrive and EQ in front is out of the question (for me and given my choice of CODE PRE AMP's I suppose). What I HAVE found though: it's MAINLY the CODE's inbuilt distortion/overdrive where the noise comes from. Turn those both off and MOST of it disappears. Problem is: I absolutely love the CODE's distortion i.e. it's can be very "lush" when combined with the CODE's reverb and delay. I was going to go out and buy a Marshall Guvnor but I read too many bad things about the "new" Guvnor's so gave it a miss. I have queried this all with Marshall and their response was that "the extra noise is caused by boosting the signal going into the Code. Digital amplifiers don't cope as well as analogue. The idea with Code is to get everything you need from the unit it'self." I don't have the knowledge to comment on this but I accept it (I sure ain't getting rid of my CODE amps. so I've made a plan, as can be seen on this thread, to overcome the problem).

    I'll tell you a little (rather embarrassing) secret though!!! Very many people I've spoken to here (locally) about these amps. haven't exactly raved about them and some have asked "well how do you get them to sound like that because mine doesn't". That type of thing. I thought, at first, it could be my guitars (a Blaze VC-II Anniversary and two Jackon's with high output ceramics) but NO (although I'm sure the guitars help). I run everything through AKG wireless systems. And never did it even cross my mind to check anything when I set this stuff up i.e. I just plugged in the wireless stuff and all sounded great (never even bothered to try an instrument cable at the time). Well as I found out MONTHS later: the wireless systems are actually outputting a LINE LEVEL signal into the amps. and this is definitely the reason why my amps sound different i.e. the wireless systems are definitely adding loads of gain at line level (as well as slightly clipping the guitar signal) (although I've checked the waveforms and it seems as though they're actually applying some type of subtle compression as opposed to simply clipping the guitar signal). I tested by turning their output (the wireless systems) down to instrument level and lost a good part of my "wonderful" sound. Strange thing is that they don't add ANY noise at all where the CODE amps. are concerned. This does lead me to question Marshall's take on this noise issue (above). But it also means that these amps. are not "shy" to take some punishment at the input. So I dunno. Call it luck. Call it a perfect combination of gear. Dunno. It just works for me!!! I know this statement is gonna get me into trouble with some "purists" for sure BUT I even did a Kemper Profiler comparison (the Kemper was plugged into a Marshall 4x12 cab.) (not sure which model it was though) and I can tell you that my CODE50's sound more "vintage Marshall" than anything on that Kemper. And I'm sure I don't have mention the difference in price!!! So yeh: to me (the CODE) "it's a Marshall"!!! LOL!!!

    I have been asked "well why not just go and buy a valve head or two" and I must admit I was very recently tempted i.e. our local dealer here had a sale and happened to have two JCM800's on the floor. But even at half the price (excluding cabs. that is): what could I do with them??? For my application they'd just be WAY too much to handle in all aspects (I remember too well what it was like to lug a valve head and cabs. around and that's just to begin with i.e. there's the output as well). And honestly: I don't think the difference between my sound from these CODE amps. and those JCM800's could warrant the substantial additional investment (as I say: for my application anyway). I saw somebody else mention (somewhere around here) that the CODE50 is a "way loud and in-your-face" amp. and I have to agree. The CODE25's have a different character altogether (which lends itself really nice to being micd. up and go through a PA or for recording with mics.). I've contemplated adding to my "CODE collection" and getting two CODE100's but I've stopped myself i.e. other than this effects loop / noise issue (now resolved) I really couldn't want for more. And it's a nice place to be for a change!!!

    Regards,

    Dale.
     
    Last edited: Sep 27, 2018
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  14. dpaterson

    dpaterson Member

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    Hello.

    I thought I'd post the below for the sake of interest as it ties up with some of the stuff mentioned earlier today (above). As I said: I reckon I'm a bit of an "authority" on these things!!! LOL!!!.

    I've spent some time doing analysis of these amps. The CODE APPEARS to do one or two weird things when certain combinations of PRE FX, PRE AMP, and CAB are selected. The pic. below is a spectrum analysis of the CODE output via USB with white noise and with DISTORTION PRE FX, JCM800 PRE AMP, 1960 CAB., REVERB, and DELAY enabled. Notice the "dip" in the spectrum within the yellow circle that I drew on the pic. It's that region that cannot be EQ'd no matter what you do (not by using the internal BASS, MIDDLE, TREBLE, or PRESENCE controls) and I think this is tied to what was mentioned above and the reason for my need of an EQ pedal. Notice also the two spikes i.e. the one just inside the yellow circle to the right and then the big spike to the right of the yellow circle just outside of the yellow circle. Those spikes are caused by certain of the CABS. in conjunction with DISTORTION PRE FX and REVERB i.e. disabling some or all of these in certain combinations eliminates those spikes. And those spikes are the cause of that "horrible dry fuzz" that you get when recording via USB or HEADPHONE/LINE OUT (they are not present when the amps. are micd. up and the spectrum is nicely rounded i.e. micd. up it falls off nicely and smoothly from around 6kHz). On the VERY odd occasion when I've actually recorded something via USB or HEADPHONE/LINE OUT I've simply filtered out those two spikes (brickwall) and there's been no perceivable loss of tops and the "fuzz" is gone. What's interesting is that if I deharmonize the analysis then the spectrum basically flat lines in those areas.

    COD JCM800.JPG

    I won't bore everyone with a multitude of combinations and their respective analyses. I think you'll get the picture.

    One thing that I do think prudent to add here though: I'm not sure just how "valid" my analysis is. In other words: none of the above is necessarily indicative of a fault or of bad design i.e. it could simply be that the "real" pieces of gear actually do react that way and that the modelling is accurate. I'm no sound engineer (but maybe there are some around who could comment on this). This being said: I've not seen these types of spectrums with any amp. sim. or IR or anything else like that (but again: not sure if this actually means anything in the bigger picture).

    Regards,

    Dale.
     

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    Last edited: Sep 27, 2018
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  15. Antmax

    Antmax Well-Known Member

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    Don't know if this is of any interest. A guy called Tony does inside out reviews and in one of them he opens up a CODE 25 and talks you through the components. Since all the CODES are similar and the FX loop on the 100 seems to be patched oddly in relation to the headphones. It might be pretty easy to modify one if you know where to look.



    Would be funny if one of those small wire harnesses could be adapted into a loop. On my DSL5c the FX loop is just a little board and a pair of wires with connectors on the end.

    It would be cool if someone did figure out how to mod one inside. Put this out here so maybe someone with a 100 might eventually check out the thread and show use what they have inside their amp.
     
  16. dpaterson

    dpaterson Member

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    Good morning.

    Thanks for the video and the pic. I must say: good 'ol Tony there on the video doesn't seem to like 'em much does he!!! And some of those comments also grated me i.e. I don't know how people can say that these amps. (especially the CODE50) are "for kids" or bedroom/practice only. Oh well. Each to their own I guess.

    I wanna tell you I'm starting to regret starting this thread!!! LOL!!! After seeing your pics. I'm now on a personal mission to find out how we can add a "proper" effects loop to these things!!! It's taking everything I have to NOT open up an amp. and see what's going on. Only thing stopping me is that (unfortunately) I'm one of those people that if I DO take an amp. apart I'll inevitably have "spares" lying around after I've put it all back together again!!!

    This has all reminded me though of one big concern I've had for a while now and that's the fact that there is absolutely NOWHERE on the Internet that sells spares for these things. One would have thought that by now there would be somebody selling spare PCB's or something for these amps. I've asked Marshall about this too and they just say to take it to your dealer and then Marshall will repair.

    Anyways. ON WITH THE MISSION!!! LOL!!!

    I watched the video (obviously) and took a good long hard look at your pic. It would not surprise me AT ALL if the effects loop connectors in the CODE100 range are also not simply on a board with those (or similar) wires coming from a connector on a main board. I took some snapshots from the video. In the first pic. it's pretty obvious that the board is the POWER AMP i.e. the speaker is connected to this board (and, as a matter of fact, somewhere else on these forums there are pics. of this same board and it was agreed on that thread that this was indeed the POWER AMP board). In the second and third pic. I've just marked two open connectors (not saying they ARE the right connectors but just saying). It could also be that any two of those white and black wires going from the "Marshall board" to the POWER AMP are simply the output just before the POWER AMP (which is exactly what we're looking for).

    I'm gonna post to ask if somebody has a CODE100H and that's willing to take some pics. for us. I'm suggesting the CODE100H for the simple reason that I reckon it will be pretty easy to see what's going on (as opposed to inside a CODE100).

    I SUPPOSE I should just take a CODE25 (to begin with) to the amp. builder that I mentioned somewhere above. Only thing worrying me is that in an email he was talking about having to add an additional board (if this was all possible that is) when fitting an effects loop so that there were no impedance mismatch problems etc. with pedals and effects. Worries me that it may interfere with the sound I get is all. But maybe it's the absolute right way to do this. No idea. Don't have the expertise unfortunately.

    Ah well. Here's the pics.

    This DEFINITELY the POWER AMP board:

    CODE Power Amp.jpg

    The following two just "ideas" i.e. empty connectors:

    CODE Conn 1.jpg

    and

    CODE Conn 2.jpg

    It's a BIT strange to me (come to think of it) that nobody has gotten to the bottom of this i.e. this is not the first thread I've seen on this very topic. But it seems the questions are asked and that's the end of it i.e. I don't know if people just give up because it's too much trouble or forget about it or if it's just not possible to do this. I guess we're gonna find out though: ONE WAY OR THE OTHER!!! LOL!!!

    Regards,

    Dale.
     
  17. ampmadscientist

    ampmadscientist Well-Known Member

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    One spark of static electricity can destroy the whole thing. The soldering iron should be ESD protected.
    It is not advisable to try a modification unless you have test equipment and tools to deal w/ digital circuits.
     
  18. dpaterson

    dpaterson Member

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    Hello.

    Well there goes that (my) plan then!!! LOL!!! On the other hand: what's the WORST that could happen (famous last words!!! LOL!!!).

    You've got nearly 9 000 posts around here though. Any ideas on this???

    Regards,

    Dale.
     
  19. ampmadscientist

    ampmadscientist Well-Known Member

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    It's possible to make a loop between preamp out and power amp in, but it's not the connector on the board.
    That connector may be for factory programming / software in the DSP.

    You need the schematics which can be obtained (maybe) from a service center.

    The worst that could happen: your amp is a door stop.
     
  20. dpaterson

    dpaterson Member

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    Hello again.

    Yeh. I figured. Was just joking around is all. CODE25 would make an attractive doorstop though let's face it!!! LOL!!! Well I do have five CODE amps. (three CODE25's). Not sure if it's worth sacrificing one "for science" though (at least not without having some more info. and a "fighting chance" of success anyway).

    Tried this more than once. No chance. Probably have an easier time getting copies of classified docs. from the CIA than getting a hold of these (for reasons I don't quite understand i.e. what would be the harm in having a simple block diagram made available???).

    More. More. (More info. I mean). Only reason I thought that it COULD POSSIBLY be a connector on the board was because of the pic. posted above by Antmax of the inside of his DSL5C i.e. those send/returns jacks are on a small board themselves and go to pins on another board. But you're probably right i.e. given that the HEADPHONE/LINE OUT disables the effects loop on the CODE100/CODE100H it's probably just some type of wiring thingy is all (and have always believed that this particular little quirk with the CODE100/CODE100H effects loop is a clue).

    Hmmmnnn... Could even be something as simple and dumb as cutting into those wires indicated on the pic. below. There's three: ground and, possibly, left and right (remember that the CODE outputs dual mono at the HEADPHONE/LINE OUT). Also make the assumption that the input to the POWER AMP board is AUDIO and not digital (otherwise my "pseudo effects loop experiment" would not have worked).

    CODE Wires.jpg

    Anyways. "Pulling at straws" here as they say. Let's see if we get some pics. from my other thread.

    Regards,

    Dale.
     
    Last edited: Sep 28, 2018
    Antmax likes this.

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