MajorNut JCM 800 Build. - Page 3

Wilder Amplification · 10-27-2009, 07:14 PM

Quote:

Originally Posted by MajorNut1967

Listen here lady bloody muck, I'm not from Australia! New Zealand was where I was brought up, not "shrimp on the barbie" LOL

We drink Double-Brown not Foster. So if you want call the Aussie's a bunch of wankers go right ahead, but don't include me.

LOL

I thought Fosters was a Canadian imitation of Aussie piss. I personally prefer Cascade Draught...straight from Hobart.

Jesstaa · 10-27-2009, 07:49 PM

Quote:

Originally Posted by MajorNut1967

Listen here lady bloody muck, I'm not from Australia! New Zealand was where I was brought up, not "shrimp on the barbie" LOL

We drink Double-Brown not Foster. So if you want call the Aussie's a bunch of wankers go right ahead, but don't include me.

Hey watch it Kiwi >.>

MajorNut1967 · 10-27-2009, 10:34 PM

Ok a few more pics. I got shorted some coupling caps .022 so just a few more parts installed. all the resistors on the power tube sockets.

Wilder Amplification · 10-28-2009, 02:56 AM

Quote:

Originally Posted by MajorNut1967

Ok a few more pics. I got shorted some coupling caps .022 so just a few more parts installed. all the resistors on the power tube sockets.

Hey Major...a little trick. Instead of jumping all the pin 8/1 together from each power valve socket you can just place a solder terminal washer on one of the mounting screws for each power valve socket at pins 8 and 1 and connect pins 8 and 1 to that.

Also, on the 100 watters you only really need a swamper resistor on the two outer valves. Lots of old Marshalls were done this way where they'd connect one swamper between V4 Pin 5 and V5 Pin 5 and the second one would be between V6 Pin 5 and V7 Pin 5, then the phase inverter outputs would connect to V5 Pin 5 and V6 Pin 5.

MajorNut1967 · 10-28-2009, 03:29 AM

Quote:

Originally Posted by Wilder Amplification

Hey Major...a little trick. Instead of jumping all the pin 8/1 together from each power valve socket you can just place a solder terminal washer on one of the mounting screws for each power valve socket at pins 8 and 1 and connect pins 8 and 1 to that.

Also, on the 100 watters you only really need a swamper resistor on the two outer valves. Lots of old Marshalls were done this way where they'd connect one swamper between V4 Pin 5 and V5 Pin 5 and the second one would be between V6 Pin 5 and V7 Pin 5, then the phase inverter outputs would connect to V5 Pin 5 and V6 Pin 5.

Oh I do something a little different with pin1. Pin1 is actually connected to the bias supply, so I prefer to feed each pin5 with its own 5.6k. It’s similar to what a Traynor YBA-3 does fun stuff! Plus you didn't see the 1ohm 2 watt 1% resistor per side of pin8 for quick bias checking.

Wilder Amplification · 10-28-2009, 03:42 AM

Quote:

Originally Posted by MajorNut1967

Oh I do something a little different with pin1. Pin1 is actually connected to the bias supply, so I prefer to feed each pin5 with its own 5.6k. It’s similar to what a Traynor YBA-3 does fun stuff! Plus you didn't see the 1ohm 2 watt 1% resistor per side of pin8 for quick bias checking.

OK that explains the blue wire...so you can measure each pair. But usually when people do the 1 ohm resistor trick they have one on each valve so they can see what each valve is drawing.

I haven't seen the scheme for a Traynor YBA-3. Where does pin 1 connect to the bias supply at?

MajorNut1967 · 10-28-2009, 03:46 AM

Quote:

Originally Posted by Wilder Amplification

OK that explains the blue wire...so you can measure each pair. But usually when people do the 1 ohm resistor trick they have one on each valve so they can see what each valve is drawing.

I haven't seen the scheme for a Traynor YBA-3. Where does pin 1 connect to the bias supply at?

Well for quick bias checks I just like to look at each side rather then each tube. And the connection for the bias to pin1 is before the 220k split.

MajorNut1967 · 10-28-2009, 11:39 AM

Well kids we are being held up by capacitors. My supplier of Mallory 150 had some sort of parts bin cross contamination and I ended up with 160 .01mfd metal film caps, so if any of you fella's need some let me know. I really don't use .01 for any thing.

Apostle Tone · 10-28-2009, 01:08 PM

I use .01uF caps, but not sure about metal film and how they would work, fit, or sound?
How much you want for them? Shipping to Colorado.

MajorNut1967 · 10-28-2009, 01:39 PM

Quote:

Originally Posted by Apostle Tone

I use .01uF caps, but not sure about metal film and how they would work, fit, or sound?
How much you want for them? Shipping to Colorado.

I only have 16 left. I'll PM you.

MajorNut1967 · 10-28-2009, 02:07 PM

Ok some of you PM me about why I put pin1 to the bias supply

"

The above wiring scheme has quite a few benefits, but please be 100% sure you know what you are doing (if not, refer to a Traynor YBA-3 schematic). To give the appearance of factory wiring, I drill two small holes on the circuit board and use similar looking wire. The above circuit will reduce secondary emission of the tube even better than the original wiring scheme. You also get improved linearity. This will end up making the tube's plate current more efficient to the point that you will have to re-bias! The last Marshall I 'modified' in this manner had the plate current increase 5mA. So, please recheck your bias after doing this procedure. Where some technicians insert a 1-ohm resistor between pin #8 (cathode) and ground, this arrangement is far 'safer' for the tube. Think about it. Instead of having the Suppressor Grid at ground potential or even at a negative voltage, you would have a positive voltage (granted only 50mVDC or so, but positive nonetheless) on that grid, because no one ever separates the Suppressor Grid from the Cathode. Where most inexperienced technicians have trouble with EL34's is in a 'poorly' designed amplifier that was biased by the current draw method via a 1-ohm resistor in the cathode! The idea presented above, in concert with an 'improved' Screen-Grid wiring scheme, yields a very efficient environment for any EL34."
(This is information is property of the TONE LIZARD) Please visit his site!

Wilder Amplification · 10-28-2009, 02:40 PM

Quote:

Originally Posted by MajorNut1967

Ok some of you PM me about why I put pin1 to the bias supply

"

The above wiring scheme has quite a few benefits, but please be 100% sure you know what you are doing (if not, refer to a Traynor YBA-3 schematic). To give the appearance of factory wiring, I drill two small holes on the circuit board and use similar looking wire. The above circuit will reduce secondary emission of the tube even better than the original wiring scheme. You also get improved linearity. This will end up making the tube's plate current more efficient to the point that you will have to re-bias! The last Marshall I 'modified' in this manner had the plate current increase 5mA. So, please recheck your bias after doing this procedure. Where some technicians insert a 1-ohm resistor between pin #8 (cathode) and ground, this arrangement is far 'safer' for the tube. Think about it. Instead of having the Suppressor Grid at ground potential or even at a negative voltage, you would have a positive voltage (granted only 50mVDC or so, but positive nonetheless) on that grid, because no one ever separates the Suppressor Grid from the Cathode. Where most inexperienced technicians have trouble with EL34's is in a 'poorly' designed amplifier that was biased by the current draw method via a 1-ohm resistor in the cathode! The idea presented above, in concert with an 'improved' Screen-Grid wiring scheme, yields a very efficient environment for any EL34."
(This is information is property of the TONE LIZARD) Please visit his site!

OK so now the "engineers" are starting to take over and push their "much better design on paper" ideas over on guitarists.

Yet all of the amps that guitarists love the sound of all have grounded suppressor grids.

I'm sure this works great in the hi-fi world. I personally have never tried this trick so I can't say either way "hey" or "nay" on the tonal difference. But my thing is, it WILL have some sort of a tonal effect and will not sound the same as what every Marshall that exhibits a grounded suppressor grid arrangement sounds like...it's worked this way for lots of years, why change it?

Just my $0.02.

MajorNut1967 · 10-28-2009, 03:14 PM

Quote:

Originally Posted by Wilder Amplification

OK so now the "engineers" are starting to take over and push their "much better design on paper" ideas over on guitarists.

Yet all of the amps that guitarists love the sound of all have grounded suppressor grids.

I'm sure this works great in the hi-fi world. I personally have never tried this trick so I can't say either way "hey" or "nay" on the tonal difference. But my thing is, it WILL have some sort of a tonal effect and will not sound the same as what every Marshall that exhibits a grounded suppressor grid arrangement sounds like...it's worked this way for lots of years, why change it?

Just my $0.02.

I just do it because of the crappy EL34's now days. But it still sounds like a Marshall, I really don't notice a tone difference. But the EL34's in a 100watt with this mod seem to last longer. And I believe it is specifec mod to guitar amps: Traynor Boogie and some others; Im not a Hi-Fi guys so don't know about that. If I was real paranoid I would do transient suppression too LOL

Wilder Amplification · 10-28-2009, 03:41 PM

Quote:

Originally Posted by MajorNut1967

I just do it because of the crappy EL34's now days. But it still sounds like a Marshall, I really don't notice a tone difference. But the EL34's in a 100watt with this mod seem to last longer. And I believe it is specifec mod to guitar amps: Traynor Boogie and some others; Im not a Hi-Fi guys so don't know about that. If I was real paranoid I would do transient suppression too LOL

By transient suppression are you referring to the backwards biased "flyback diodes" you see from the plate to ground? I like to run those with the JCM900 valve fail fuse/LED arrangement.

You may be onto something here Major. Like I mentioned before I have a Super Lead build on the bench as we speak so I just may have to try this out. If we can get longer valve life without sacrificing tone I just may have to follow suit.

Oh crap...I just caught the "be sure that you know 100% what you're doing" disclaimer so this mod won't work for me.

00jett · 10-28-2009, 04:44 PM

First off, I am really learning alot from you guys in this thread. I don't pretend at all to know what you guys are talking about, but i have read through alot that tone lizard site a while ago for kicks i guess. He seems to take alot from the traynor designs, which are known to sound very marshall like and be much easier on tubes. i talked to a collector on time that said old el34 traynor designs were rated for much higher wattage than marshall amps and still lasted way longer. Neway i really like watching this build!

MajorNut1967 · 10-28-2009, 04:56 PM

Quote:

Originally Posted by Wilder Amplification

By transient suppression are you referring to the backwards biased "flyback diodes" you see from the plate to ground? I like to run those with the JCM900 valve fail fuse/LED arrangement.

You may be onto something here Major. Like I mentioned before I have a Super Lead build on the bench as we speak so I just may have to try this out. If we can get longer valve life without sacrificing tone I just may have to follow suit.

Oh crap...I just caught the "be sure that you know 100% what you're doing" disclaimer so this mod won't work for me.

LOL

thats right fly-back diodes not the LED disco lights. Smart little buggeration aern't you!

Wilder Amplification · 10-29-2009, 02:12 AM

Quote:

Originally Posted by MajorNut1967

LOL

thats right fly-back diodes not the LED disco lights. Smart little buggeration aern't you!

Smart "alec"...remember? Specializing in navigating the "map of tazzie".

MajorNut1967 · 10-29-2009, 11:18 AM

Quote:

Originally Posted by 00jett

First off, I am really learning alot from you guys in this thread. I don't pretend at all to know what you guys are talking about, but i have read through alot that tone lizard site a while ago for kicks i guess. He seems to take alot from the traynor designs, which are known to sound very marshall like and be much easier on tubes. i talked to a collector on time that said old el34 traynor designs were rated for much higher wattage than marshall amps and still lasted way longer. Neway i really like watching this build!

Hi Jett,

The lizard is from Canada so amps Traynor & Garnet are favorites of his. But for Traynor not being a well know amp they sure are built well and extremely loud. Traynor's practice of tying the BIAS feed to the G3 on the EL34's is why they could be pushed so hard and not have tube blow outs. I worked on one Traynor in my life, supposedly a 100 and it scoped out at 130 watt constantly at 1k @ 650mV. So plenty out put!

I hope that some how we are helping you a bit in learning this stuff, I'm no expert myself so I learn from all the guys here. But there are a few Blokes here who really know there stuff and impart their knowledge to everyone. Those are definitely the guys to stay in-tune with. Good Luck!

MajorNut1967 · 10-29-2009, 05:45 PM

Ok we got Iron. Here's the X-fers I got from Magnetic Components Inc.

Wilder Amplification · 10-29-2009, 06:02 PM

Quote:

Originally Posted by MajorNut1967

Ok we got Iron. Here's the X-fers I got from Magnetic Components Inc.

I wonder why they drilled the chassis to mount the transformers backwards like that. Not referring to the fact that they're 90* off like they are (they're supposed to be) but the core of the OT usually runs the length of the chassis while the PT core usually runs the width of it.

MajorNut1967 · 10-29-2009, 06:11 PM

Quote:

Originally Posted by Wilder Amplification

I wonder why they drilled the chassis to mount the transformers backwards like that. Not referring to the fact that they're 90* off like they are (they're supposed to be) but the core of the OT usually runs the length of the chassis while the PT core usually runs the width of it.

Actually I re-drill the chassis to fit like that. I learned it from some old dinosaur friend of mine and for some reason it seem to keep the stray fields at bay better.

Wilder Amplification · 10-29-2009, 06:18 PM

Quote:

Originally Posted by MajorNut1967

Actually I re-drill the chassis to fit like that. I learned it from some old dinosaur friend of mine and for some reason it seem to keep the stray fields at bay better.

OK I know about the whole "put your own spin on it" shit but damn Major...fuck Marshall. You should create your own brand.

Apostle Tone · 10-29-2009, 07:06 PM

Since I've never built a Marshall style amp I have a noobie question.

It's those big cans sticking out on the bottom ~ I believe they are the filter caps. Are these the same as say a Fender would have on a power board mounted sideways? In other words are they electrolyic caps mounted on the chassis instead of a separate power board?

Wilder Amplification · 10-29-2009, 07:14 PM

Quote:

Originally Posted by Apostle Tone

Since I've never built a Marshall style amp I have a noobie question.

It's those big cans sticking out on the bottom ~ I believe they are the filter caps. Are these the same as say a Fender would have on a power board mounted sideways? In other words are they electrolyic caps mounted on the chassis instead of a separate power board?

That is correct. Electrolytic caps come in a few different varieties, i.e. axial lead, radial lead, and multisection. The cans you see are of the multisection variety since they actually have two caps in one can that share a common negative terminal.

The earlier Marshalls (pre-68) had the axial lead ones on a power board under the chassis like the Fenders did. The '67-'68 ones that used this technique used one multisection can paralleled for double the capacitance for the phase inverter filter cap while the rest were on a board under the chassis.

MajorNut1967 · 10-30-2009, 12:04 AM

Quote:

Originally Posted by Wilder Amplification

That is correct. Electrolytic caps come in a few different varieties, i.e. axial lead, radial lead, and multisection. The cans you see are of the multisection variety since they actually have two caps in one can that share a common negative terminal.

The earlier Marshalls (pre-68) had the axial lead ones on a power board under the chassis like the Fenders did. The '67-'68 ones that used this technique used one multisection can paralleled for double the capacitance for the phase inverter filter cap while the rest were on a board under the chassis.

Ya! What he said, that's it.

MajorNut1967 · 10-30-2009, 12:31 AM

A little Side-bar about the caps in the tone stack & treble peakers. There seems to be tendency to use silver-mica caps here by the young guys. They are usually either 500pF, 470pF or 250pF. Marshall almost always used Ceramic Disc here and they do sound different. The ceramic caps are part of the Marshall sound. The Vintage nuts say "Sliver-Mica are truly the only vintage tone caps!", well they have been making Ceramic Disc caps have been around since 1913, how much more vintage can you get? In the long run it's up to you, Mica caps are smoother sounding and the Ceramics are more biting and bright.

Wilder Amplification · 10-30-2009, 01:00 AM

I just got the heater string done in mine...so the shitty part's over. Almost got the power valve sockets all wired up. Next I'll be doing the power and standby switches, fuses, etc etc. Hopefully tomorrow I'll be able to fire up the power supply and form the filter caps.

End of next week I have a Bluesbreaker Reissue coming in for a full overhaul. Doing up a point to point board for it with all carbon comp resistors, Sozo caps, and installing a Mercury Magnetics Radiospares clone tranny in it along with a new Merc Mag choke as well. I've also reworked the tremolo circuit to the Fender LDR coupled trem circuit. Can't wait to see how that build turns out. Last thing we're doing is dropping the filter cap values back down to where an early Bluesbreaker would've been (stock the reissues are dual 50uF all the way through whereas the originals used a dual 32uF and a dual 16uF.

MajorNut1967 · 10-30-2009, 01:02 AM

All the iron is connected and I did the preliminary DC voltage test. The wave looks nice and smooth. The the "no-load" voltage was 511.6 VDC for HT, the Bias maxed was -47.5. More later. Here's a few more pics.

Ya ya its a rats nest, but we are test still.

MajorNut1967 · 10-30-2009, 11:06 AM

Quote:

Originally Posted by Wilder Amplification

I just got the heater string done in mine...so the shitty part's over. Almost got the power valve sockets all wired up. Next I'll be doing the power and standby switches, fuses, etc etc. Hopefully tomorrow I'll be able to fire up the power supply and form the filter caps.

End of next week I have a Bluesbreaker Reissue coming in for a full overhaul. Doing up a point to point board for it with all carbon comp resistors, Sozo caps, and installing a Mercury Magnetics Radiospares clone tranny in it along with a new Merc Mag choke as well. I've also reworked the tremolo circuit to the Fender LDR coupled trem circuit. Can't wait to see how that build turns out. Last thing we're doing is dropping the filter cap values back down to where an early Bluesbreaker would've been (stock the reissues are dual 50uF all the way through whereas the originals used a dual 32uF and a dual 16uF.

Hey Jon,

Do you use your drill to twist your AC fil wries? sounds like you are getting close fire up time?

I think the JTM deserves P2P board. I don't use carbon comps unless the customer demands them, too noisy. Did they request the Sozo caps or is that just what you use? I don't know why Marshall upped the cap values, an of the shelf RI don't even sound like a 45! Sounds more JTM 50'ish. are going to return to the old values on the first cathode & the tone stack ?

belch · 10-30-2009, 12:34 PM

I find it easier & much neater to use teflon coated wire twisted with a drill for the heaters, it stays where it's put due to the extra rigidity.

Still a pain in the arse though, just had to do a 9005.

10-27-2009, 10:34 PM	#63 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: MajorNut JCM 800 Build. Ok a few more pics. I got shorted some coupling caps .022 so just a few more parts installed. all the resistors on the power tube sockets. __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's

10-28-2009, 11:39 AM	#68 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: MajorNut JCM 800 Build. Well kids we are being held up by capacitors. My supplier of Mallory 150 had some sort of parts bin cross contamination and I ended up with 160 .01mfd metal film caps, so if any of you fella's need some let me know. I really don't use .01 for any thing. __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's

10-28-2009, 01:08 PM	#69 (permalink)
Apostle Tone Member Join Date: Oct 2009 Location: Colorado Posts: 35	Re: MajorNut JCM 800 Build. I use .01uF caps, but not sure about metal film and how they would work, fit, or sound? How much you want for them? Shipping to Colorado. __________________ Ignorance+Ego+Insecurity+Technology=funny

10-28-2009, 02:07 PM	#71 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: MajorNut JCM 800 Build. Ok some of you PM me about why I put pin1 to the bias supply " The above wiring scheme has quite a few benefits, but please be 100% sure you know what you are doing (if not, refer to a Traynor YBA-3 schematic). To give the appearance of factory wiring, I drill two small holes on the circuit board and use similar looking wire. The above circuit will reduce secondary emission of the tube even better than the original wiring scheme. You also get improved linearity. This will end up making the tube's plate current more efficient to the point that you will have to re-bias! The last Marshall I 'modified' in this manner had the plate current increase 5mA. So, please recheck your bias after doing this procedure. Where some technicians insert a 1-ohm resistor between pin #8 (cathode) and ground, this arrangement is far 'safer' for the tube. Think about it. Instead of having the Suppressor Grid at ground potential or even at a negative voltage, you would have a positive voltage (granted only 50mVDC or so, but positive nonetheless) on that grid, because no one ever separates the Suppressor Grid from the Cathode. Where most inexperienced technicians have trouble with EL34's is in a 'poorly' designed amplifier that was biased by the current draw method via a 1-ohm resistor in the cathode! The idea presented above, in concert with an 'improved' Screen-Grid wiring scheme, yields a very efficient environment for any EL34." (This is information is property of the TONE LIZARD) Please visit his site! __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's

10-28-2009, 04:44 PM	#75 (permalink)
00jett Senior Member Join Date: Jan 2009 Posts: 133	Re: MajorNut JCM 800 Build. First off, I am really learning alot from you guys in this thread. I don't pretend at all to know what you guys are talking about, but i have read through alot that tone lizard site a while ago for kicks i guess. He seems to take alot from the traynor designs, which are known to sound very marshall like and be much easier on tubes. i talked to a collector on time that said old el34 traynor designs were rated for much higher wattage than marshall amps and still lasted way longer. Neway i really like watching this build!

10-29-2009, 05:45 PM	#79 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: MajorNut JCM 800 Build. Ok we got Iron. Here's the X-fers I got from Magnetic Components Inc. __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's

10-29-2009, 07:06 PM	#83 (permalink)
Apostle Tone Member Join Date: Oct 2009 Location: Colorado Posts: 35	Re: MajorNut JCM 800 Build. Since I've never built a Marshall style amp I have a noobie question. It's those big cans sticking out on the bottom ~ I believe they are the filter caps. Are these the same as say a Fender would have on a power board mounted sideways? In other words are they electrolyic caps mounted on the chassis instead of a separate power board? __________________ Ignorance+Ego+Insecurity+Technology=funny

10-30-2009, 12:31 AM	#86 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: MajorNut JCM 800 Build. A little Side-bar about the caps in the tone stack & treble peakers. There seems to be tendency to use silver-mica caps here by the young guys. They are usually either 500pF, 470pF or 250pF. Marshall almost always used Ceramic Disc here and they do sound different. The ceramic caps are part of the Marshall sound. The Vintage nuts say "Sliver-Mica are truly the only vintage tone caps!", well they have been making Ceramic Disc caps have been around since 1913, how much more vintage can you get? In the long run it's up to you, Mica caps are smoother sounding and the Ceramics are more biting and bright. __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's Last edited by MajorNut1967; 10-30-2009 at 10:53 AM.

10-30-2009, 01:02 AM	#88 (permalink)
MajorNut1967 Senior Member Join Date: Jul 2009 Location: South Pacific Posts: 710	Re: MajorNut JCM 800 Build. All the iron is connected and I did the preliminary DC voltage test. The wave looks nice and smooth. The the "no-load" voltage was 511.6 VDC for HT, the Bias maxed was -47.5. More later. Here's a few more pics. Ya ya its a rats nest, but we are test still. __________________ MJN1967 aka BA (Bad Attitude) 1968 model 1987 50watt. A Baby Major (Half-Power) I built from the ground up. JTM 45 Clone combo Ground up build. JCM 800 Clone Ground up build. Custom Built Warmoth Strat 75' Fender Tele-Deluxe '70 style strat custom build w/Custom Shop 69's PU's Last edited by MajorNut1967; 10-30-2009 at 11:08 AM.

10-30-2009, 12:34 PM	#90 (permalink)
belch Member Join Date: Sep 2009 Location: Brew town UK Posts: 40	Re: MajorNut JCM 800 Build. I find it easier & much neater to use teflon coated wire twisted with a drill for the heaters, it stays where it's put due to the extra rigidity. Still a pain in the arse though, just had to do a 9005.

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