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EL 34 question

I have a VAC PA 35.35 EL 34 push-pull amp, that has had factory upgrades. I was quite happy with it, until I started using a modified SET 300B amp, which has blown the VAC completely out of the water.

I am actually giving thought to selling it, but decided to see if tube rolling might bring it closer in performance to the SET amp.

I have two sets of output tubes that are used, a matched quad of reissue Genelex KT 77, and a matched quad of reissued Mullard EL 34's.

The small tubes are NOS Telefunken 12AU7 and 12AT7, all aound three years in use.

I'm just hoping I can get some insight as to whether better performance can be gleaned from this old amp.

My experience with tubes is recent, lots I don't know, so any old salts that care to help with suggestions would be great.

By the way, the speakers are 94db sensitive custom Tannoy HPD's.

Best regards,
Dan
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Showing 3 responses by islandmandan

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islandmandan OP
1,260 posts
 
Thanks Ryriken,

I checked last night, thinking I had the Mullard reissue EL 34's in but, instead, the EH EL 34's were in. I quickly swapped the Mullards back, and the amp sounded a bit better, but still no match for the SET 300B mesh plates.

I'll see if some 6CA7 Fatboys can be found and give them a try.

Regards,
Dan
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islandmandan OP
1,260 posts
 
Thanks guys, for your responses. I have been more than mildly surprised by the improvement wrought by the modest Assemblge SET 300B, however, it does have fresh factory upgrades w/new carbon film reisitors, Jupitor foil and paper beeswax capacitors, and it just seems to keep getting better and better.

I won't give up on the VAC yet though, until I do a bit more tube rolling. It's still a very good amp, with high current output. I'll see how it goes.

Thanks again,
Dan
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islandmandan OP
1,260 posts
 
I've got a line on some 6ca7 Fatboys, I'm going to give them a try.

There's no question, the SET 300B is my go-to amp (system sounds its best in forty five years of trying).

I like having an alternative to turn to, for variation, and for back-up. The VAC is a very different beast (about 80lbs; mostly in iron), and has some advantahes for highly dynamic music.

Thanks to all for your contributions. Regards,
Dan
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