# Converting to Bass Amp Head



## bcmatt (Aug 25, 2007)

I have a Traynor YGL-3a head that gets used mostly for bass. When I first got it, it was used that way by the previous owner too. I was surprised when I found out it was made for guitar.

I do like the sound for guitar, especially the tremolo/reverb channel, but I rarely use it anyways, because I usually have a bass player using the amp. I am thinking of getting another bass cab to use with it with 10 inchers in it.

Anyways, are there some simple and obvious mods I should do to voice it more appropriately for bass? Did I hear something about doubling up the cap values on the tone controls? Is that true? I just got "The Tube Amp Book" a couple days ago that includes a ridiculous amounts of schematics in it. Should I try comparing the schem with the YBA-1 or something and changing the preamp to that? What are parts of the circuit that I should focus my attention on? Is there another bass amp schematic that would be more appropriate to look at?

I am open to doubling the phase inverter caps too if that seems like a good idea, but my thoughts are to leave things so that the reverb channel is unaffected. However, if it makes real positive difference to the bass guitar tone then it is worth it since it is still primarily used for bass. If it would make a great bass amp, then I am willing to do a lot of changes to the circuit and that will be it's mission in life.
Thoughts anyone?


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## bcmatt (Aug 25, 2007)

So, after looking at a lot of the Traynor Bass Amp Schematics 
I see a number of differences that keeps me from copying preamps 
(since that thought crossed my mind if they were close enough).

First of all, my YGL only uses 2 12ax7 gain stages(a single 12ax7) 
before the phase inverter tube, while most of the bass amps use 
3 or 4 gain stages there.

Second of all, it seems that none use a mid control, 
but rather they have treble and bass controls and then 
a low end expander and a high end expander. 
I guess that's how Traynor did it.

Are there other schematics I should look at to influence 
my choices? I thought of the Ampeg SVT schems 
(hey, lets dream big, eh?), but again, those tone-stack schematics 
take vastly different shapes to my eyes.


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## bcmatt (Aug 25, 2007)

Click on this for a pic of the YGL-3a schematic if it didn't appear in the last post:
http://2.bp.blogspot.com/_4u9l5q2yF...AApA/WwHogVdixIU/s1600/721020_YGL3_3A_Mk3.gif


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## bolero (Oct 11, 2006)

I don't think you need to mod the amp at all, those old traynors sound great for bass

you could put 6550 power tubes in, to boost the clean output, but that may involve some minor modification


I have a YBA3 custom special that sounds amazing for gtr or bass, & it's stock


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## bcmatt (Aug 25, 2007)

bolero said:


> I don't think you need to mod the amp at all, those old traynors sound great for bass
> 
> you could put 6550 power tubes in, to boost the clean output, but that may involve some minor modification
> 
> ...


It doesn't sound too bad right now; you are right. However I am wondering if I should modify the tone controls to be more appropriate. 
I will think about the tube change. I think I saw something about what needs to be changed for that to be done in the Tube Amp Book.

I think the YBA was originally designed to be for bass, so that why it would be voiced so well for it I think. My YGL was more designed after a Fender Twin to be used for guitar. 
But you know, maybe I should get a new bass cabinet (2x10) or 4x10 and maybe that will help give me a little more punch than the 1x15 I have right now.


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## bolero (Oct 11, 2006)

go here, & click on "amps" at the top left....post the same question in that forum: there are a lot of great amp techs who frequent that boad & lots of tech questions


http://www.webervst.com/vstbbs/bbs.html


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## dwagar (Mar 6, 2006)

I'd suggest you beg, borrow or steal a couple of different bass cabs and test it out. That may be all you really need to change.


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## bcmatt (Aug 25, 2007)

dwagar said:


> I'd suggest you beg, borrow or steal a couple of different bass cabs and test it out. That may be all you really need to change.


Ya, I'm thinking you might be right. I will see if I can find a 2x10 to try in parallel with my 1x15.


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