Traynor YBA-1 Mods?

Dennis Detweiler · Post by **Dennis Detweiler** » 9 Jul 2014 7:38 am

I have a 1970 Traynor YBA-1 head and 4X10 matching speaker cabinet in great condition. I had the head spec'd soon after I got it. I've read that it was built in relation to the early Fender amps. Are there any basic mods to bring it closer to the 59 Bassman characteristics?

Joel McCoy · Post by **Joel McCoy** » 9 Jul 2014 9:24 am

Hey there. I have a '71 YBA-1 and have found this site helpful...http://www.kilback.net/traynortweaks.htm

The YBA-1 is in basic terms a Canadian JTM-45 (Marshall) which is in turn a British copy of a 57-59 Bassman. Some values in the components are different and there are the 6CA7's (or EL-34's) instead of 6L6's (or 5881's) in the Bassman. Most guy's want to take the YBA into full-on JTM-45 land instead of the lower gain Bassman land. Try putting a 5751, or 12AU7 in the V1 position and it'll clean up..Along with some nice 5881's.
Hope this helps...

Joel

James Quackenbush · Post by **James Quackenbush** » 9 Jul 2014 1:08 pm

http://www.0rigami.com/vb/index.html

Darrell Birtcher · Post by **Darrell Birtcher** » 9 Jul 2014 5:47 pm

The March 2008 Vintage Guitar magazine had a good write up about this amp. If you can find it, the info might come in handy.

Dennis Detweiler · Post by **Dennis Detweiler** » 9 Jul 2014 6:55 pm

Thanks to all. I have info to mull over. I think I'll start with the tube substitution and then tone stack parts and see how effective the results will be. I'm happy with my Revelation and rack gear for pedal steel. I'm trying for a more vintage setup for my lap steel. And, since I already have the YBA-1, I thought I'd make use of it.

Walter Killam · Post by **Walter Killam** » 11 Jul 2014 7:56 am

I have a YBA1 that I was planning to do mod to, and ended up with supply caps & a pair of Svetlana BLUE\HARD tubes, and decided that other mods were not necessary.

It works great for Bass & Pedal Steel, I'm not changing anything else on it.

Jerry Hedge · Post by **Jerry Hedge** » 11 Jul 2014 6:09 pm

Those Traynors are tied for my second favorite tube pedal steel amp. (the other one one is an Ampeg SVT) My number one is my tricked out Twin Reverb!!! Pete Traynor used an old Mullard circuit. He was able to hit the plates of the output tubes with about 540 to 560 volts and got about 90 watts out of a pair of 6CA7/EL34. Other people were using lower voltages and only getting 50 watts from them.

David L. Donald · Post by **David L. Donald** » 14 Jul 2014 3:22 am

Most Traynors were highly under-rated by most.
I have a YGM3 Guitarmate combo and it is a really killer little amp.
A few minor mods and it became a real screamer,
and nicely clean till it went wild.

Roy Buchanan played the YBA1 for years.

Dennis Detweiler · Post by **Dennis Detweiler** » 20 Aug 2014 2:10 pm

I have the tone stack narrowed down to what I want to hear from it. The mods shown on the internet are for guitar and, maybe more specifically, rock guitar. After experimenting with lap steel with Alumitone pickup, I narrowed it to:
1M volume pots
C5= 250pF SM
C6= .1uf orange drop
C7= .022uf orange drop
R15= 100k

This seemed to lower the treble hz and allow the Presence control to be more useful.
I'd rather see the Bass and Treble setting positions reversed, but it works. Settings are (o'clock):
Treble= 3:00
Bass= 10:00
Low (mid)= 10:00
High (presence)= noon

Playing into a JBL D-130F

John Limbach · Post by **John Limbach** » 1 Sep 2014 9:15 am

Dennis:

Glad you're a few weeks ahead of me. Saving me some false starts!

I'm waiting for parts to come in so I can start the mod process. It works pretty well as is, so I've been playing my Ricky through it and messing with the settings to try to get a baseline sound in my head before making changes.

What's your take on the master volume control mod? Is it needed for steel? I was thinking of adding a version of the antennuator circuit from the later Traynor's, although maybe only three positions, 40W, 20W, and 10W. Since the only place I'm going to use it is in my basement, seems like maybe I could reduce the power and maybe extend the life on the EL-34s.

Maybe could do that with the master volume circuit mod. Doesn't if effectively reduce the power without affecting the tone? Or am I missing something?

John

Mike Neer · Post by **Mike Neer** » 1 Sep 2014 12:30 pm

You guys should check out Kevin O'Connor's (London Power) books. He is a Canadian and is well familiar with Traynors. There is one book in particular that he wrote that addressed Traynor amps. I used to have it, but no longer do. Working on tube amps was a passing phase for me.

http://www.theultimatetone.com/

John Limbach · Post by **John Limbach** » 1 Sep 2014 12:33 pm

Mike:

Yeah, buddy, that's the bible. Mine is heavily underlined, bookmarked, and dog-eared.

By the way, I have your book too. Enjoy your blog and have learned lots. Thanks for the time you put into it.

Dennis Detweiler · Post by **Dennis Detweiler** » 2 Sep 2014 7:58 am

I'm as far as I'm going with it for now. I like what I'm hearing and don't think I have to dive into any more circuit mods.
I've also been using the Boss 59 Bassman stomp box. For some reason, I get crunch or distortion at subtle settings in line before entering the guitar input of my Revelation. But, the Rev is used for my Pedal steel and don't want to patch the Boss through the effects patches with my TC Electronics processor. However, I get a nice clean 59 Bassman in front of the Traynor input and use this setup with my lap steel.

John Limbach · Post by **John Limbach** » 21 Sep 2014 9:06 am

Dennis:

I've got my YBA-1 up and running now. Pretty much did the same mods as you, and left the tone stack alone. I find the treble control to be very noticeably effective while the bass control is a lot more subtle. Still not sure what I think of the mids and presece controls. Am using it with my Ricky B6 to a Peavey speaker that I swapped out of my N112 for an EPS 12.

Sounding good so far. How you liking yours now that you've used it a while?

John

Dennis Detweiler · Post by **Dennis Detweiler** » 22 Sep 2014 7:35 am

John, I like it pretty good. I think a little more presence control dominance would be good. If I could set the bass around 3:00 and the treble at 10:00 instead of the reverse, I think I would have a little more control over it and it would be closer to steel amp settings. A slight more dip in the mids would be good.
I like it with the boss bassman 59 pedal to tweak my tone slightly. I like the sweep of the new volume pot. Good for now.

Lane Gray · Post by **Lane Gray** » 22 Sep 2014 8:43 am

Dennis, I gotta ask because I'm a curious sort: Why does it matter where the controls are set to get a good tone? As long as it gets to a good tone, I'd be happy.
Personally, as long as Traynor used round shafts, I'd just find the good settings, pull the knobs off, align them to what you're used to seeing on your amp and slide them back on.
PS: since I could never remember where I liked the phase on the Session 500 or the tremolo on the 400, I dialed in my effect, slid the knobs off, and put them back on pointing at 12 o'clock. Worked great until I sent the amp to the shop. The tech moved them back to sweep from 7 to 5. Oh, well.

Dennis Detweiler · Post by **Dennis Detweiler** » 22 Sep 2014 9:06 am

Hi Zane, those amp techs always want to set the knobs back to factory.
You're right, it doesn't really matter where the knob is pointing as long as it sounds good to the ears. For some reason, there's a spot (I'll call it sweet spot for reference purposes)where the tone breaks drastically and then tapers off before or after that sweet spot on the pot. Maybe it has to do with the tone stack components? I don't know for sure? But, when I dial in an amp, I usually find that spot where it breaks and dial it slightly left to rid the harshness of bass, middle or treble. It just seems more controllable if I have more room on either side of it. I like it somewhere between 11:00 and 2:00 to allow me more room for tapering it. Maybe if I change the values of the treble and bass stack a little it will move that sweet spot? My two Session 400's the mid control sweet spot is in the vicinity of 8:00 to 9:00 which is fine for my taste, since I take advantage of the dip that's built into the amp. I like the bass and treble in the 12:00 plus range to allow a little more flexibility for adjustment. But, that's just me.

John Limbach · Post by **John Limbach** » 22 Sep 2014 10:08 am

Dennis:

Reference to the numbers on the dial, and not the clock, mine is (for the moment) Treble=2, Bass=9, Low=4, High=3

This is with the big horseshoe in the Ricky B6 driving it through a Sarno BB. Should run without it for a while until I finish dialing in the tone since the Vari-Z on the BB changes the tone as well.

It's a fun machine all right. I replaced the first preamp 12AXY7 with a 12AY7 to drop the gain a bit but with the volume on the Ricky at about 50%, any setting on the Traynor volume above 5 starts melting the wax in my ears.

Did you do the presence control mod? I've got a 5K pot inbound and will try it and see what if any difference I can hear.

Dennis Detweiler · Post by **Dennis Detweiler** » 22 Sep 2014 1:00 pm

I didn't do a presence mod. Let me know the outcome of the pot exchange.

John Limbach · Post by **John Limbach** » 22 Sep 2014 1:49 pm

Dennis:

This is the schematic of my YBA-1. Found it glued to the bottom of the lid, which is pretty thoughtful. Is it the same as your unit? I'm looking at what you replaced in the tone stack and wanted to make sure the cap and resistor numbers are the same as mine, or what the equivalent are on mine.

Wish I had your problem with the bass. I run mine nearly all the way up, say 4 or 5 o'clock and the treble only about 9-10 o'clock and still wish for more bass.

I get a lot more bass backing off on the treble than I do advancing the bass control.

Will let you know how the presence works out. It's basically just lowering the value of the pot and taking the 4,700 ohm parallel resistor out. Easy enough to put back in if it doesn't do anything good.

See my last couple of posts in the YBA-1 Effects Loop thread and you'll know right where I'm at with it. Sure is easy to work on and try things out.[/img]

John Limbach · Post by **John Limbach** » 22 Sep 2014 2:00 pm

And of course I just noticed that there are two sets of capacitors marked C4 and C5, now that will make you crazy!

Dennis Detweiler · Post by **Dennis Detweiler** » 22 Sep 2014 4:28 pm

It's not the same numbered schematic as the one that I used. Transposing to your numbers:
C6 = 250pf
C7 = .1
C8 = .022
R16 = 100k

I pulled the schematic from the internet. However, I didn't look under the top panel of the cabinet. Maybe the original is there?
Also, the mod schematic that I found is the one that I used to make the changes which uses C5, C6, C7, R15 on its schematic. So, its confusing.

John Limbach · Post by **John Limbach** » 23 Sep 2014 7:25 am

Yep, it is confusing all right.

What difference did changing R16 make in the sound?

Also, I changed the .001 cap going from V1 to the channel 2 volume control to 250pf. It was excruciatingly bright with the .001. Actually sounded pretty good just with it removed but I decided there might be some utility to having a brighter channel. Not sure though because channel 1 is brighter than I would like already! I have a switch on both volume controls now so maybe I'll use one to switch that "bright" cap in and out.

Craig Baker · Post by **Craig Baker** » 23 Sep 2014 1:06 pm

John,
Looking at the schematic as posted, changing coupling capacitors C5 / C22 / C7 from .01 to .047 or .05 might let more low frequencies pass through. Also C3 and C4 on the input circuit may help if they were larger value also. Keep in mind, the "bright" cap across the volume control will have less and less effect as he volume is increased. On the other hand, placing the "bright" cap across R12 would offer a consistent high boost. Please keep the forum posted.

Best regards,
Craig Baker 706-485-8792

cmbakerelectronics@gmail.com

C.M. Baker Electronics
P.O. Box 3965
Eatonton, GA 31024

John Limbach · Post by **John Limbach** » 23 Sep 2014 2:01 pm

Thanks Craig, I will play around with that tomorrow and see how it goes.

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Traynor YBA-1 Mods?

Traynor YBA-1 Mods?

YBA-1 Mods...