Valve amps are better for your figure

Conclusive proof comes from this auction for a solid-state AC30:

Now I don't feel so bad about lugging my 4xEL34 heads around the place.

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His spine is probably still ok tho....

Is it a solid state? the amp that is, not the seller.

1bassleft wrote:
...comes from this auction for a solid-state AC30

I guess so. :D

It's definatly a Valve amp.... sorry Bass.

Looking at the logo and everything else, Lee, I think you're right. But too late :evil: :lol: . I don't really care about bidding serious money for them, but it looks like £475 was a serious steal. I just assumed it was the '70s SS version after the Thomas Organ deal. Speaking of which, shall we run a sweepstake on when this seller last saw his "Thomas Organ"? :)

No Standby swich usualy means SS, but i think the early 70's Vox Valve AC30's didn't use a standby. But all the heat vents gives it away.

I've never really spent time on researching AC30s. I know there are plenty of sites that would make dating a relative breeze. Lacking a standby switch is often a sign of valve rectification. Because the valve takes time itself to warm up, no standby is necessary but a switch to SS diode rectification means that the power valves get the DC instantly, hence the standby. Hmmm, a valve-rectified AC30 would be highly prized and, although I'm not bothered myself, I know people who would happily pay me rather more than 500 quid for one. I'm feeling a bit of a chump now :oops:

I thought it was the other way around, valve rectifier = standby switch, im pretty sure that early 70's one would be a Rose Morris which had SS rectification, and no standby, where as the later Korg Reissue had a standby and valve GZ34 rectification, ive not checked any of this out, its just from memory, i might have it all arse :shock: about face..

I believe you're right on the Vox but wrong about the theory. The original Voxes had no standby switch even with diode rectification, something the Korg reissues have rectified (ouch :oops: ). If a valve, like the GZ34 or EZ81, did the rectifying, then the power valves (the EL84s) don't get an immediate blast of DC before they've warmed up. Diode rectifiers send it straight through, so a standby is a good idea to let the heaters warm up.

HST, my CMI-Marshall has no standby and the Mullard EL34s lasted for donkeys and the Svets put in around 2000 are still there (although the amp was gigged a lot less from then).

Now I think about it, none of my WEM Dominators has a standby, including the 30W and the RSC GP30 I've just sold (also cathode-biased, maybe Class A) didn't have one either. Bit mystifying, because I can't see any reason why cathode-biasing saves the valves from torture. EL84s were/are a lot cheaper than the EL34, but that doesn't explain the absence on the RSC. I suppose that cathode-biasing means that, if a tube goes kaput, you simply buy a replacement and drop it in, whereas fixed-bias amps would require a new set and re-biasing. Expensive and tedious enough to warrant fitting a standby circuit.

Incidentally, all Doms I've bought still had their 70s Mullard EL84s in there so a standby isn't the big deal you'd think. The only exception was that 30W version (parallel push-pull, still cathode biased), bought for 41 quid as a non-worker. It had three Hungarian Tungsrams and a nasty, dead, Chinese EL84 that can't cope with the screen current of old amps. Replacing the Chinee with a Tungsram got it working fine.

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