HELP! about traynor yba-1a

[MAMMOTHvolume]

YBA-1A Bass Master Mark II

Features: Same as YBA-1 except for a fan mounted in the side (1960s) or internally (1970s), also good for guitar - tubes were also same as the YBA-1

Approximate Serial Number: 0200 to 1800's = 1968 to 1970
006#### to 605####

Years Made: 1968-1976

Amp Type: Tube Head

Power: 90 Watts Sine Wave @ 8 Ohms

Comments: Same output tubes (two 6CA7s) as the YBA-1?! Yes, bigger transformers, filter caps, and fan cooling made it work.

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Music City in North Bay, Ontario, Canada used to rent the YBA-1A Mark II out with the YC-610 (5.3 Ω ) for bass use all the time, but going down to 4 Ω might be risky.

it'll be 50watts looking at the schematic, it is possible to get 100watts out of a pair of el34 types but theres noway your gonna get 90 out of them in ultra linear

 

[projectMalamute]

it'll be 50watts looking at the schematic, it is possible to get 100watts out of a pair of el34 types but theres noway your gonna get 90 out of them in ultra linear

I don't think any of the old Traynor's are using an ultralinear tap on the transformer.

Here's a bunch of old schematics, including the YBA-1Am mk II:

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[BassmanPaul]

it is possible to get 100watts out of a pair of el34 types

Read post #18.

Paul

 

[BeauZooka]

Regarding the original post: I have a late 60's YBA-3 that I just got worked on. It puts out 100 watts at 4 & 16 ohms and 120 watts at 8 Ohms. So at least for my model, 8 Ohms is optimal. But it should be able to handle 4 ohms no problem.

 

[Lammchop93]

I had a 1968 model of what you are getting. I couldn't turn it up past 35% volume without it fuzzing. It might have been because I only have active basses. Ending up selling it a guitar player. Sounds amazing for guitar.

 

[kraigo]

I had a 1968 model of what you are getting. I couldn't turn it up past 35% volume without it fuzzing. It might have been because I only have active basses. Ending up selling it a guitar player. Sounds amazing for guitar.

I get around that by using lower gain preamp tubes.

KO

 

[Rhomco]

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I often use my YBA-1 for bass but only when I want a nasty tube tone. Good rocker bass amp but not for clean power. That price ($400.00) is a excellent to fair price and remember this amp is among the best out there for Marshall/Vox AC-50 tones on guitar.
I'd hit it! but I already have a BassMate, BassMaster and a VoiceMaster modded for fouir channel guitar.
Great stuff,
Rob

 

[DanGouge]

I know the power ratings on the YBA-1A are a source of controversy and frankly I don't know anywhere near enough to comment intelligently on how many watts one of these things generates, but I have tried them out in a store and heard them played live with loudish bands and however much power they make, they sure do seem cut through. Kind of dirty sounding - very much a rock amp, but seriously loud.

 

[jerkass9879]

I just wanted to say thanks to everyone who replied. I got the amp 2 days ago and all I can say is wow!!!. this thing sounds incredible and has sooooo much power. I used it at a smallish venue (250ppl max) with nothing in the pa besides kick drum and vocals and it never went past 4 1/2 on the volume and even that was still probably too loud. 10 out of 10 so far. and thanks again.

 

[mongo2]

I just wanted to say thanks to everyone who replied. I got the amp 2 days ago and all I can say is wow!!!. this thing sounds incredible and has sooooo much power. I used it at a smallish venue (250ppl max) with nothing in the pa besides kick drum and vocals and it never went past 4 1/2 on the volume and even that was still probably too loud. 10 out of 10 so far. and thanks again.

You're making me want to gig mine again but then I remember lugging that beastie around and I think I'll stick to my Shuttle 6.