DSL401 - Bass boosting patch cable

JohnH · 05-12-2009, 04:47 PM

Here is how to build a bass-boosting patch cable, using the FX loop to add more low end to the DSL401 OD channels.

The parallel loop has some gain built into it. ie, if you bridge it with a patch lead between send and return, and turn up the FX mix knob, you get about a 6-7 db boost. Now if, instead of a straight wire, you bridge the send and return through a resistor and capacitor acting as a filter, you can make it just a bass booster. Turning up the FX then gives about 6db extra bass.

To make this bass-boost patch cable, you need two jack plugs and about 6"of screened cable. Connect the screen ground to each plug as usual, but for the centre core, insert a 47k resistor somewhere in the line between the two jack plug tips. Finally, a 10nF cap goes from jack tip to ground, at the return end. I put one at the send end too, so it does not matter which way round I plug in the cable. I managed to get at the parts inside the jack plugs.

First one end; theres a yellow 10nF cap soldered between the jack tip and jack ground. That gets done first, as tightly as you can. Then theres a 47k resistor with one end soldered to the jack tip, the other end to the cable centre core. THe cable ground goes to the jack plug outer ground connection, as for a normal jack cord. I also put some insulated sleeve over the resistor to stop it shorting

Here's the other end, which is the same except no resistor. Put the cap in first between tip and ground connections, then connect the cable as for a normal jack plug

Completed, with outer sleeves retracted

In place between send and return, pumping up the bass!

With a cap at both ends, it makes no difference which way round you place the cable between send and return.

You can buy parts from anywhere that sells them, so long as you get those values, which are common, it does not matter what style of cap you get. Phyically smaller is better however, to get it neatly in the plug. If you are in the US, mouser.com is very good.

Yiou might like to experiment before you solder up, by plugging in just the front part of the plugs into the send and return, and wiring it up with alligator clips. The key connections are ground to ground, resistor between hot and hot, and a cap between ground and hot at the return end. Increasing the resistor focusses more on the lower tones, but with less gain boost available.

Turn the amp FX up full. The overall effect is not bone-crushingly dramatic, but it is easy and gives a nice extra low end kick in OD mode, approximately doubling the range of he bass control, which is something that these amps need. On the clean channel, it has a smaller effect.

cheers

John

Lindgren · 09-24-2009, 10:05 AM

Very nice, i will try that myself. Thank you.

JohnH · 09-25-2009, 06:28 PM

Well good luck - if you do, please post a comment. This really works, but its specific to the DSL401 , andt Im only aware of one other guy who's tried it. He was pleased with it too.

John

Lindgren · 10-25-2009, 05:03 PM

Okey John, im heating up my soldering iron right now.
Have'nt had the time until now because of my work.

What do you think will happen when using the bass boost cable in the loop at the same time as my TC Nova Delay ?
Should i put the cable in front of the delay or after ?

Btw, i have done the heatsink mod and also put in a cooling fan which i power from the main switch, just like you did. It work's great.

JohnH · 10-25-2009, 09:28 PM

Lindgren - the bass boost cable is a neat trick, but it needs to be the only thing in the loop because it only lets bass through - everything else goes throug the direct path in the amp, and this works because t is a parallel loop . Its worth a try, but you' d have to put your effects all in front of the amp, which is what I do. If you like the idea of boosting bass in this way, I have an active version, with 3 transistors that works more awesomely, or just use an EQ box in the loop.

John

Lindgren · 10-26-2009, 08:28 AM

Quote:

Originally Posted by JohnH

Lindgren - the bass boost cable is a neat trick, but it needs to be the only thing in the loop because it only lets bass through -

John

So i've noticed, it didn't work any good together with the delay pedal in the loop.
I have to buy me a EQ pedal instead but otherwise it's a really good way to boost some bass on the OD channels.

05-12-2009, 04:47 PM	#1 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	DSL401 - Bass boosting patch cable Here is how to build a bass-boosting patch cable, using the FX loop to add more low end to the DSL401 OD channels. The parallel loop has some gain built into it. ie, if you bridge it with a patch lead between send and return, and turn up the FX mix knob, you get about a 6-7 db boost. Now if, instead of a straight wire, you bridge the send and return through a resistor and capacitor acting as a filter, you can make it just a bass booster. Turning up the FX then gives about 6db extra bass. To make this bass-boost patch cable, you need two jack plugs and about 6"of screened cable. Connect the screen ground to each plug as usual, but for the centre core, insert a 47k resistor somewhere in the line between the two jack plug tips. Finally, a 10nF cap goes from jack tip to ground, at the return end. I put one at the send end too, so it does not matter which way round I plug in the cable. I managed to get at the parts inside the jack plugs. First one end; theres a yellow 10nF cap soldered between the jack tip and jack ground. That gets done first, as tightly as you can. Then theres a 47k resistor with one end soldered to the jack tip, the other end to the cable centre core. THe cable ground goes to the jack plug outer ground connection, as for a normal jack cord. I also put some insulated sleeve over the resistor to stop it shorting Here's the other end, which is the same except no resistor. Put the cap in first between tip and ground connections, then connect the cable as for a normal jack plug Completed, with outer sleeves retracted In place between send and return, pumping up the bass! With a cap at both ends, it makes no difference which way round you place the cable between send and return. You can buy parts from anywhere that sells them, so long as you get those values, which are common, it does not matter what style of cap you get. Phyically smaller is better however, to get it neatly in the plug. If you are in the US, mouser.com is very good. Yiou might like to experiment before you solder up, by plugging in just the front part of the plugs into the send and return, and wiring it up with alligator clips. The key connections are ground to ground, resistor between hot and hot, and a cap between ground and hot at the return end. Increasing the resistor focusses more on the lower tones, but with less gain boost available. Turn the amp FX up full. The overall effect is not bone-crushingly dramatic, but it is easy and gives a nice extra low end kick in OD mode, approximately doubling the range of he bass control, which is something that these amps need. On the clean channel, it has a smaller effect. cheers John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

09-24-2009, 10:05 AM	#2 (permalink)
Lindgren Junior Member Join Date: Sep 2009 Location: Artic circle - Sweden Posts: 26	Re: DSL401 - Bass boosting patch cable Very nice, i will try that myself. Thank you. __________________ ESP Eclipse NR1 ESP Eclipse NR2 ESP Eclipse NR3

09-25-2009, 06:28 PM	#3 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: DSL401 - Bass boosting patch cable Well good luck - if you do, please post a comment. This really works, but its specific to the DSL401 , andt Im only aware of one other guy who's tried it. He was pleased with it too. John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

10-25-2009, 05:03 PM	#4 (permalink)
Lindgren Junior Member Join Date: Sep 2009 Location: Artic circle - Sweden Posts: 26	Re: DSL401 - Bass boosting patch cable Okey John, im heating up my soldering iron right now. Have'nt had the time until now because of my work. What do you think will happen when using the bass boost cable in the loop at the same time as my TC Nova Delay ? Should i put the cable in front of the delay or after ? Btw, i have done the heatsink mod and also put in a cooling fan which i power from the main switch, just like you did. It work's great. __________________ ESP Eclipse NR1 ESP Eclipse NR2 ESP Eclipse NR3

10-25-2009, 09:28 PM	#5 (permalink)
JohnH Senior Member Join Date: May 2008 Location: Wollongong NSW Posts: 640	Re: DSL401 - Bass boosting patch cable Lindgren - the bass boost cable is a neat trick, but it needs to be the only thing in the loop because it only lets bass through - everything else goes throug the direct path in the amp, and this works because t is a parallel loop . Its worth a try, but you' d have to put your effects all in front of the amp, which is what I do. If you like the idea of boosting bass in this way, I have an active version, with 3 transistors that works more awesomely, or just use an EQ box in the loop. John __________________ DSL401 8412 cab Crate Powerblock 1 x 12 Vintage 30 cab '76 Shergold Masquerader '93 Les Paul Studio '83 Roadstar

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