Hahahaha... that just made my day. The bottom line is, in a circuit like the ES-1 is very easy to use different tubes. Now whether it is a good idea is debateable but I don't think it is a great idea to run some of these tubes on a +400v PSU. When I modified the circuit for the A11 I would only use ECC99's in the second stage due to their high voltage capability and it's only running at +350v. I stuck a ECC83 in the first stage to get the high gain but I've yet to try how it behaves at full power.
Damn this sucks. If you can open the amp and PSU up and post some Hi-Q pictures then we might see what's gone wrong.
Marc, isn't it about time the whole family got together for some soldering fun?
I'd take caps in the signal path over the danger of exploding Li-Ion batteries. Just imagine how crappy the other RSA amps are (such as the cRaptor) as they have coupling caps and cheap electrolytic output caps.
I wouldn't mess with the socket personally, I would rather measure the socket/pins and make short jumper leads. Make sure they are properly insulated since there is a lot of voltage coming from those transformers.
Both did since they were made of the same/similar material. You can read about this glorious new material on the ECR800 page on TVK which was supposed to sound so good but had broken down into some sticky mess when I got them.
Thanks for the pics. It is certainly better made then some of the other clusterfucks, it even has heatshrink over exposed wire and the soldering isn't all utterly terrible. I don't know what's up with the coupling caps since they appear to be serial connected 0.01uF units which are way too small for this amp. The V+ for the last stage looks to be uninsulated (the left side of the large resistors towards the back of the amp) which is just asking for trouble. There is only a single filament supply (which drives the LED indicator as well) which means the amp will not be easy on the output tubes. If will be a pain to strip the chassis if mine is like that...
I have the same problem.
Impressions will come and comparisons against the A11 (mini ES-1). Considering that it would be tough to make the A11 for more then 1k$ (if you stick with sensible parts) then it should be an interesting comparison. I need to increase the voltage in the PSU though and get rid of that channel imbalance but not enough time and I will be working the whole weekend...
I have to dismantle it first to see what parts need to be ordered and to know what I'm dealing with. The main focus is on the PSU (i.e. how much space I have in there) and how that digital output stage bias setup works. Odds are that it is a 20$ voltmeter with two pots but we'll see. While I have it open I'll change it over to 230v and then use it for some time, while parts arrive and I build all the upgrades. I have some cool things planned but that mostly depends on the space available in the PSU chassis. Let's just say there will be some small elements of the SRM-T2 in the operation of the amp...
Perhaps but Marc is right, short of the V-caps, BG's etc. crammed into those boxes there isn't much that is worth saving. The 45 step attenuators would be one thing but knowing I'd have to redo all of those solder joints just gives me a headache.