Traynor YBA 1 Bassmaster "One Wire" mod

[copperheadroads]

This `is the other Traynor I own its the YBA 1 & I've got the traynor tweaks mods done & new filter caps ,but I would like to keep this one more like a plexi style amp & do the "one wire mod" on a push pull if possible or use it as is used with a plug inserted in the jack but as I don't have cliff jacks this might not be an option
please let know what you think
the yba has .022uf coupler caps on both channels & these plans says to swap them around but one in these plans are .0022uf so i guess i will replace one on
volume II
did some searching found this ... which don't look that difficult
here is the basic procedure for making that modification to your amp.
It will put you pre amp section in cascade (series) to add gain....
Gain factor will be multiplied when in series instead of adding itseft in parallel (as it is normaly know, stock)...

This is for Super Lead type amp but you can do it on similar amp also... If you want to maximise this mod do a swap of caps before you begin.....

The VOLUME II channel should use the .0022uF for coupling cap
and the VOLUME I bright channel should use a .022uF coupling cap...also you should use the tone stack withthe 250pF on the treble with 56K slope resistor...also use .1uF for the PI caps....

Go to the VOLUME II pot....unsolder the wire in the center terminal of the pot wiper...then solder this wire to GROUND, you can just solder it to the next pin on the same pot that is grounded...

the mod itseft:Take a 1 MEG resisitor and solder it to the center wiper.... then take the other end of the 1Meg resistor and solder it to the junction of the 68K input resistors of CHANNEL 1 .........ie you solder it where the two 68K resistors are joined together for channel 1 ... Now yo are done.... now plug guitar into channel II then turn the Channel I and Channel II volume to 10 then keep the MAster Volume to control the volume.... You should now have a good amount of gain and crunch.... Now to add extra gain and crunch you will need a 1/4 male jack only with no cable attached to it.....take this plug and stick it into channel 1 jack and you will now get even more gain.....

For those wanting to try this mod it is imperative to have a Master Volume with your amp, if not it will work but won't sound very good, The MV will limit and control it, etc, Post Phase inverter master volume will do it perfect.....!!!

Here's a link http://www.marshallforum.com/index.p...e-wire-mod.97/

[loudthud]

There is a new version of the YBA-1 that Traynor is selling now. It has a DPDT switch to accomplish the cascade arrangement. I saw the schematic on the Traynor website. The disadvantage is that both Volume controls are in the signal path and there is really not much gained by that. In one of my amps I used a 3PDT to bypass the 2nd Volume pot.

The .0022 cap cuts too much bass for my taste. It's OK in a plexi when you are using both channels in parallel because you can use both the channel volumes to dial in the treble-bass balance. For my money I say go straight to the JCM 800 2204 circuit and dial up the gain on the cold clipper stage to suit your style and you can get enough distortion before the Master. Fewer layout hassles and the Master Volume is on the front panel.

[copperheadroads]

There is a new version of the YBA-1 that Traynor is selling now. It has a DPDT switch to accomplish the cascade arrangement. I saw the schematic on the Traynor website. The disadvantage is that both Volume controls are in the signal path and there is really not much gained by that. In one of my amps I used a 3PDT to bypass the 2nd Volume pot.

The .0022 cap cuts too much bass for my taste. It's OK in a plexi when you are using both channels in parallel because you can use both the channel volumes to dial in the treble-bass balance. For my money I say go straight to the JCM 800 2204 circuit and dial up the gain on the cold clipper stage to suit your style and you can get enough distortion before the Master. Fewer layout hassles and the Master Volume is on the front panel.

My other amp the YBA mark II i did the jcm circuit ,I'd like to keep this one in the more like a plexi & add some gain on a switch

[loudthud]

So you have a Master Volume on the back of the amp? Is it the PPIMV type? If you have a Volume pot with a DPDT switch, I would modify the above description and not simply connect to the 68K resistors. I have a schematic somewhere on how to do this or you can look for the new YBA-1 schematic.

[loudthud]

These schematics show a "Both" input for plexi mode.

[copperheadroads]

Yes it has a PPIMV & the input resistors are on the jacks of the yba which makes it a easy mod ,I will try it with stock 0.022uf caps as i don't have higher enough voltage 0.0022uf cap
It may roll off too much bass i think i will try a .001

[Matt T.]

FWIW, using a PPIMV at anything other than very loud volumes essentially defeats the Presence control. So you're basically NEVER using the Presence and always reaching behind the amp for the MV. I always move the Presence to the back and put the PPIMV on the front. Layout-wise it works really well too.

[KevinOConnor]

Hi Guys

Loudthud: Do you have that schematic for the "new" YBA1? Can't find it on Yorkville's site nor the Traynor site.

You can link the inputs internally using the closed contacts on the jacks - no need for a "both" jack - but this is much simpler if there is one jack per channel. I did this on my 2-ch Sustainor preamp to allow the player to have separate effects feeding the two channels or to drive both channels as usual.

The mods that change the plexi input to an 800 necessarily have both controls in the signal path as one becomes 'gain' and the other 'volume'. This gives three gain stages in the preamp to make decent 70s distortion sounds. The 2-stage plexi pre even with inputs bridged can only muster mild overdrive on its own, which is why the PPI-MV is implemented when one is trying to retain the aesthetic of the plexi circuit. As others note above, this is a compromised approach.

Have fun

[g1]

Kevin, the re-ish schematic is listed on the Traynor site as 'YBA-1mod1'. (support > manuals)

http://traynoramps.com/downloads/ser..._yba-1mod1.pdf

[KevinOConnor]

Hi Guys

Thanks for the link!

In this amp, each input stage plus its level control are treated as a "block". A relay places them in series or parallel, the latter being the stock "plexi" format. In series, one level acts as a gain and the other as a volume, allowing the mild overdrive of the two stages to be fed to the next stage and on to the EQ and PA. Nothing like an 800 mod where one can get smoothly saturated distortion.

Have fun

[copperheadroads]

Hi Guys

Loudthud: Do you have that schematic for the "new" YBA1? Can't find it on Yorkville's site nor the Traynor site.

You can link the inputs internally using the closed contacts on the jacks - no need for a "both" jack - but this is much simpler if there is one jack per channel. I did this on my 2-ch Sustainor preamp to allow the player to have separate effects feeding the two channels or to drive both channels as usual.

The mods that change the plexi input to an 800 necessarily have both controls in the signal path as one becomes 'gain' and the other 'volume'. This gives three gain stages in the preamp to make decent 70s distortion sounds. The 2-stage plexi pre even with inputs bridged can only muster mild overdrive on its own, which is why the PPI-MV is implemented when one is trying to retain the aesthetic of the plexi circuit. As others note above, this is a compromised approach.

Have fun

how do one apply this to an old YBA-1 or YBA-1a ?

[KevinOConnor]

Hi Guys

Look at the schematic for the old Traynor and you see it is essentially the same as a plexi. All you have to do is look inside the amp to see how the layout works and go from there. It's simple but you risk having to take a step towards reading schematics.

Have fun

[copperheadroads]

Anyone got good software to do an amp layout I've tried a couple but i never get all the components to do the layout

[olddawg]

Hi Guys

Look at the schematic for the old Traynor and you see it is essentially the same as a plexi. All you have to do is look inside the amp to see how the layout works and go from there. It's simple but you risk having to take a step towards reading schematics.

Have fun

Yep.... and people have an irresistible urge to mod sometimes when the stock configuration is optimum. It's all subjective, but have you simply tried putting a TS type pedal Straight in to it? You might have better results than chopping it up.

[copperheadroads]

It's modded now to the plexi & i boost it with a sd-1 it's a great classic rock tone but with a push pull to get into jcm territory sounds interesting & makes it more versatile for my playing style .
I tried the 1 wire mod & I got a little confused & reversed it .
everything is laid out opposite on the Traynor compared to the marshall
tube sockets are turned around ,channels are arranged in reverse as well as the volume controls .