1972 yba1a

S

simoon

high everybody.i just picked up a mint yba 1a. just wondering what mods can be done and what the general opinion is on these amps.thanks
 

Tone_Terrific

Silver Supporting Member
Messages
33,731
Plug into ch2 jumper to ch1, balance to taste, go outboard for od.YMMV.
Don't mod it unless you know why you don't like it and know what you will end up with.
 

ROKY

Member
Messages
7,231
I had 2 '68 YBA-1As, sold one last winter, still have one.

The YBA-1As are beasts, lots of muscle, loud(how did Pete do it?)
Mine is as loud as my Marshall Super Lead.

Seriously.

I wouldn't necessarily mod mine; just plug and play !

Earplugs maybe ...:D
 

cameron

Member
Messages
4,203
There's no reason to mod it unless it's too bright for you. (They can be very bright sounding.)

They're great amps, but, as the previous responders noted, extremely loud. Easily as loud as a 100 watt Marshall. To look at the schematic, they obviously bear a family resemblance to the Tweed bassman, and the early Marshall circuits. But to listen to them, they're in some ways more like their Hiwatt contemporaries.

What I like most about them is their ability to give you great grind and crunch, but without losing low-end definition. No mush to those amps. I attribute this to the over-sized transformers, which are much bigger and heavier than what you find in the comparable Marshalls.
 

ROKY

Member
Messages
7,231
Originally posted by cameron
There's no reason to mod it unless it's too bright for you. (They can be very bright sounding.)

They're great amps, but, as the previous responders noted, extremely loud. Easily as loud as a 100 watt Marshall. To look at the schematic, they obviously bear a family resemblance to the Tweed bassman, and the early Marshall circuits. But to listen to them, they're in some ways more like their Hiwatt contemporaries.

What I like most about them is their ability to give you great grind and crunch, but without losing low-end definition. No mush to those amps. I attribute this to the over-sized transformers, which are much bigger and heavier than what you find in the comparable Marshalls.
Well said... spot on, actually :AOK


The output tranny on mine is 3" and the power tranny just short
of 4"

We're talking early Marshall Super Lead dimensions! :eek:

I think by the early 70s they had downsized them.

The one I sold to a forum member had been modded, I suspect.
The sound and response was indentical to my Super Lead; they
even started to breakup at the same point on the volume.

This is especially intersting to me because, again a Super Lead
uses 4 EL34s and the YBA-1A,of course just 2.

Pete Traynor was able to design the output section as such to
squeeze, about, 90 apparent watts out of 2 output tubes.:confused:

The 1A that I still have needs a tweak or two as it's a little brighter than the first
I suspect the first one had a lower value bright cap installed and
a few other 'tweaks'.

The Hiwatt comparison is very appropo.

I also have 2 YBA-3s made in '67 that get an incredible, sort of,
Blonde Showman/Hiwatt-esque crunch starting at about 5 on the
volume.

I bought that first one to have a bass amp; this after I'd been
getting into the Traynors for a few months.

Not only was it a great bass amp, as you would imagine, but when
I plugged in a guitar and wound it up, the particular tone I was
getting spun me right out.

The second I found a second one(virtually it's twin) I snagged it .

The YBA-3 Custom Specials are awesome, in their own right.
 

cameron

Member
Messages
4,203
Originally posted by ROKY

Pete Traynor was able to design the output section as such to
squeeze, about, 90 apparent watts out of 2 output tubes.:confused:

He just designed to what a pair of EL-34s is capable of. The reason Marshalls are so much lower in power is that the original Marshall designs were very closely based on the Tweed Bassman circuit, which used 6L6 or 5881 tubes (depending on which iteration of the circuit you look at). Jim Marshall just made the minimal changes to the circuit to support EL-34s, which resulted in the classic Marshall design, but which really wasn't getting all the power he could have out of the tubes. The designers at Traynor and Hiwatt actually built their output sections around the EL-34 (strictly speaking 6CA7 tubes in the case of the Traynor) tubes, and thereby got a good deal more power out of them.
 

jonny guitar

Member
Messages
324
My 68 (with choke) weighed more than the 4x12 cab. I had to sell it becaus it was killing me to move it around.

Look at the size of those trannies.
 

ROKY

Member
Messages
7,231
Originally posted by cameron
He just designed to what a pair of EL-34s is capable of. The reason Marshalls are so much lower in power is that the original Marshall designs were very closely based on the Tweed Bassman circuit, which used 6L6 or 5881 tubes (depending on which iteration of the circuit you look at). Jim Marshall just made the minimal changes to the circuit to support EL-34s, which resulted in the classic Marshall design, but which really wasn't getting all the power he could have out of the tubes. The designers at Traynor and Hiwatt actually built their output sections around the EL-34 (strictly speaking 6CA7 tubes in the case of the Traynor) tubes, and thereby got a good deal more power out of them.
Makes sense, to me.

When I get around to it I'm going to try Sylvania 6CA7s in one
of my YBA-3s for guitar and squeeze in some KT88s in the other
for Bass .

Should be very interesting .:cool:
 

ROKY

Member
Messages
7,231
Originally posted by jonny guitar
My 68 (with choke) weighed more than the 4x12 cab. I had to sell it becaus it was killing me to move it around.

Look at the size of those trannies.
Yup there she is :dude
Looks indentical to mine(same year, so, no surprise, there..)

Unreal iron in those things:eek: :D
 

jonny guitar

Member
Messages
324
Originally posted by ROKY
Yup there she is :dude
Looks indentical to mine(same year, so, no surprise, there..)
Have you discovered that lubricating your fan with teflon grease makes it virtually silent?
 

ROKY

Member
Messages
7,231
Originally posted by jonny guitar
Have you discovered that lubricating your fan with teflon grease makes it virtually silent?
No, but ****thank you**** for mentioning that !!!!!!!!!!!!

My YBA-3 fans are both too loud :mad:

Where would I lube those girls up ??:eek:
 

jonny guitar

Member
Messages
324
Originally posted by ROKY
No, but ****thank you**** for mentioning that !!!!!!!!!!!!

My YBA-3 fans are both too loud :mad:

Where would I lube those girls up ??:eek:
Whoops, sorry about the delay.

I used a teflon based grease that is actually made for Mountain Bikes...it worked fine. I am sure that you could use a light gauge machine oil too. It is really easy to apply it: just unscrew the middle part of the fan with a flat head screwdriver and squirt it on in. Silent operation.
 

Deaj

Member
Messages
4,674
Originally posted by cpokay
I love a good Traynor thread!! Don't mod that YBA-1A unless there's something about it you don't like!! Switching preamp 12ax7s to NOS (I recently found a NOS Realistic LifeTime 12ax7wa (made in USA) works beautifully in V1) or better tubes (especially in V1 position) can make a huge difference in your overall tone, and having a really nice solid set of 6CA7 or EL-34s (I am using EH now, and I LOVE them in my Reverb Master) is also KEY to getting great sounds out of your Traynor. +1 on the other comments re: the huge transformers giving the amp its bawlz and wattage output.
Cpokay's YSR-1 (mostly a YBA-1 with reverb and tremolo) is one of the best sounding amps I've ever played and it's bone stock. No need to mod - these things rock!
 

Shemp

Member
Messages
981
It's the perfect platform for a Fuchs mod. My YBA1 mod from Andy was pushing 84 watts from a pair of el 34s. With KT 90s it was up near 100.

Heavy mofo however.
 

cocheese

Silver Supporting Member
Messages
2,550
I've had a 68 YBA-1 (now with my brother) and a 65 Yba-1 (still have). They are just great amps, period. The 68 is much louder and more Hiwatt/Marshall than the 65 which is more Tweed Bassman-esque. The 65 is not nearly as loud as the 68 which is a real paint peeler.

My bro had a master put on his 68 which made it more giggable without shattering eardrums. I heard him with it live a few times and on recordings and it sounds simply fanastic. It has a Marshall kind of thing but is mostly Hiwatt to my ears. It has that clarity like Hiwatts have. Has all the drive but keeps you from getting lost in the mix.

My 65 has 1 Meg pots in it which is a mod that the previous owner had done. I cannot tell you whether it is a worthy mod because I never heard it before, but I can tell you that it sounds great now! :D
 




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