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Traynor YBA-1A
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Friday, 23 June 2006

Well, here is my latest project. My girlfriend's nephew wanted a good tube amp. I was going to build him an AX84 HO (well, something closer to the SEL, i.e. an HO with a 6550 output section). He needed a loud amp as he is playing with a very loud drummer. I was telling a recent acquaintance that I just started building tube amps. Well, as luck would have it, he had an old and very loud tube amp that he wasn't using. He said he got it for 30$ somewhere in the 70s. He told me that there were issues with it. I offered him to repair the amp for free. That's when he told me that he didn't use the amp at all and if I wanted it, he would give it to me for free (thanks Craig!). Who can pass up such an offer? Turns out that the amp is an old Traynor YBA-1A Mark II. In essence, this is an old clone of a Marshall 1959 super lead.

I got the amp and was expecting the worst. To my amazement, it was in very good shape. The filter cap cans looked new. Tested all tubes and found that all three preamp tubes (Mesa SPAX7) were bad. Before firing up the beast (this thing puts out 90watts!), I did the following modifications:

  • replaced the high expander pot with a master volume
  • added a cathode bypass cap to the second stage triode to increase gain

Plugged the amp in and boom, beautiful and loud! This thing, although a bit dark, has that very nice Marshall crunch! Not bad for a donor amp!

Here are some pictures (click on them to enlarge them).


Inside shot

Closeup of the controls

Dreadful sound clip

This is a very quickly recorded sound clip. This does show the marshall type crunch and also some very sloppy and bad playing on my part. Click here to listen to the clip.


Last Updated ( Friday, 23 February 2007 )