Traynor YBA-1A Mark II

ko stradivarius · #1 04-12-2010, 11:46 AM

I had a bit of GAS and just picked one of these amps up this past weekend. It appears to be an early 70's model but I honestly don't know much about them. It sounds pretty nice through my Genz Benz neo 1-12 though.
So will it do 4 ohms with adding another 8 ohm cab to the extension cab output? Yes, this part confuses me.

It still has the 2-prong plug on it, which I need to replace as well.
Any good resources on these amps?
Also, it has Sylvania EL34 tubes in it. Were these stock tubes with these?

Thanks in advance.

Jim Campbell · #2 04-12-2010, 11:51 AM

Quote:

Originally Posted by ko stradivarius

I had a bit of GAS and just picked one of these amps up this past weekend. It appears to be an early 70's model but I honestly don't know much about them. It sounds pretty nice through my Genz Benz neo 1-12 though.
So will it do 4 ohms with adding another 8 ohm cab to the extension cab output? Yes, this part confuses me.

It still has the 2-prong plug on it, which I need to replace as well.
Any good resources on these amps?
Also, it has Sylvania EL34 tubes in it. Were these stock tubes with these?

Thanks in advance.

i dont recall the ohms from way back but i used those with traynor 8x10 and 2x15 cabs with no problem

cripula · #3 04-12-2010, 12:14 PM

Some good info here:

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

and here's the model-specific info:

http://www.0rigami.com/vb/models.htm...stermkiiyba-1a

It's designed to use an 8 ohm load AFAIK. There is a Yahoo Traynor group, quite a few folks there run them at 4 ohms, though I haven't been comfortable enough to do so with mine.
I love this amp. Mine was converted to run 6550s and it sounds GREAT.

BassmanPaul · #4 04-12-2010, 12:14 PM

I've see these amps with EL34s, 6CA7s, 7027s and 6L6GCs. One even had 6550s. It's a basic 50W amp.

Paul

Calaverasgrande · #5 04-12-2010, 12:29 PM

YBA1a is 90 watts (yes a pair of EL34/6CA7 can do 90 watts at 6-700 volts)
YBA1 is 45.
Thats sine wave though, so expect more.
I kept blowing mine up by running it at 4 ohms. So I would stick to 8 ohms if you play loud. If you do 4 ohms, dont push it very hard, it could be okay at lower volumes.
besides the hammond transformers these things take arent cheap. Likely $150-200 if you blow it!

IIRC the bass cabs that go with these were 16 ohms, so two in parallel would be 8.
I need to get one again.

ko stradivarius · #6 04-12-2010, 03:39 PM

Thanks. Those leads get me pointed in the right direction. First order of business is to replace the power cord.
I have a friend that will give me an old ampeg 8 ohm 2-15 cab. But, I'm not sure I want to lug it around. There's a local guy who can build me a fearful 15/6 so I may go that route after saving up some money.

BassmanPaul · #7 04-12-2010, 03:45 PM

Quote:

Originally Posted by Calaverasgrande

YBA1a is 90 watts (yes a pair of EL34/6CA7 can do 90 watts at 6-700 volts)

70W with a plate at 800V. All the YBA1s I have encountered were running below 500V

Paul

#8 04-12-2010, 03:52 PM

My '72 YBA1A MkII was tested many times, and produced a strong 90 watts BEFORE distortion!!

I used it with quite a few cabinets, and it will work with 4 ohms all day long. However, it will distort more easily than at 8 ohms, and the clean sound isn't as nice, and of course has less headroom. It will also run 16 ohms... But it is best suited at 8 ohms (and was designed for 8 ohms). Your idea of a 15/6 is perfect!

I believe the Sylvania could be OE, but likely were replacements. The OE tubes on both of my Traynors from that era were Philips brand (Mullard EL34s!!).

Unfortunately, I just sold mine to pay for other things...

MAMMOTHvolume · #9 04-12-2010, 03:54 PM

Quote:

Originally Posted by BassmanPaul

70W with a plate at 800V. All the YBA1s I have encountered were running below 500V

Paul

i've seen a pair of el34s do over 100watts in an old geloso, those amps were way ahead of their time.

#10 04-12-2010, 03:56 PM

Forgot to mention Velvet Black is a good resource...

http://www.informatik.uni-bremen.de/~dace/vb/

ko stradivarius · #11 04-12-2010, 08:17 PM

Quote:

Originally Posted by tifftunes

I used it with quite a few cabinets, and it will work with 4 ohms all day long. However, it will distort more easily than at 8 ohms, and the clean sound isn't as nice, and of course has less headroom. It will also run 16 ohms... But it is best suited at 8 ohms (and was designed for 8 ohms). Your idea of a 15/6 is perfect!

I believe the Sylvania could be OE, but likely were replacements. The OE tubes on both of my Traynors from that era were Philips brand (Mullard EL34s!!).
:

I believe this. When I run the amp through my 8 ohm Genz 1-12, like I said, it sounds great. When I run it through my Genz 2-12 it distorts a lot sooner and , well, doesn't sound as good.

I looked at the 12AX7A tubes tonight and 2 of the 3 are Philips tubes, the other is a brand Ive never heard of ( of course I already cant remember what it was now).

Calaverasgrande · #12 04-12-2010, 09:03 PM

Quote:

Originally Posted by BassmanPaul

70W with a plate at 800V. All the YBA1s I have encountered were running below 500V

Paul

again the YBA1 is 50 watts
the YBA1-A does 90.
I have owned the YBA1a and YBA3
my tech at the time benched the YBA1a at 95 watts and was kinda freaked out by it! The YBA3 benched at 130.
Of course if a tube amp will do 90 watts before it goes into clipping you can be sure it will do quite a bit more with clipping!

It is nothing new that EL34s can be run that hard, they just generally arent. I do recall chewin thru power tubes about every 6 months on that head.