spritzer

The real problem with these is that they have to be messed with. My ECR600 had a nasty channel imbalance which never went away and that cable... yeah... it has to go as it is dangerous.

I saw a set of two with an energizer going for 1300$... that is beyond insane.

I might do a version of this circuit with SS CCS just to make it a lot less complicated.

Have you seen the asking prices of ET1000 sets these days? People are nuts...

Find a cheap set of SR-507's...

Computers also have so many internal SMPS that feeding it all from a linear one is just silly.

It's excellent, nothing short of that for an all tube design. Gives the BHSE a run for its money...

Yup and many have issues with the epoxy coating so they could short out. I've lost count of how many I had throw out due to that. That's why I stick with the CMF60

I had one of those once so I have a pretty good idea what the ECR800 is like on the inside. Well that and the horrible cable...yuck!!! Turns to goo... I've seen 400$ for the earpads at some time if you can get somebody to sell you a set.

I was tempted by the SRA-8S but it is identical to the SRA-7S aside from some humpots so I passed. Not going through that restoration hell again... Nice ECR-800 but pretty useless without the adapter.

Now, now stop this!!! You are worse than the cultural revolution!!! I so wished I was there but about 5 weeks until I'll be in NYC...

I finally finished this one today after about... 4 years or so... Let's just say that I hate anything with umbilical cables... Besides the madness of using 4 mains transformers and the super short filament winding's for the CCS tubes this was easy enough. Running at +/-400V off a BHSE power supply with the dropper resistor and zeners to feed the front end. Only main difference is the 12VDC supply used to heat the front end tubes so the board was cut up pretty bad. Next one will use the Megatron V2 pcb's in about 3 years or so...

Could very well be. Hard to know exactly what is going on though...

Nope...didn't even know about them... Can you send me a link?

There could maybe be some small improvements here and there but the over all nature of this amp would be classified as "tricky". Super high voltage plus the PSU being an integral part of the output stage will always make it so. I did study ways of making the amp safe to use for anybody but in the end it just wasn't worth it.

That one is wholly incompatible with electrostatic use.

That is the easiest problem in the world to solve so yeah... I doubt that has caused any delays. The combo of D/S gap plus the bias sets the efficiency. The drive voltages naturally matter and so does the tension but D/S and bias matter the most. From what I've heard, the issue is creating drivers which are actually stable. Nothing more than rumors on that but yeah...might be some truth to that.

I never use thermistors and usually use 3.15AT fuses in all my amps. 2AT is fine for the KGSSHV at 230V. For a 300VA transformer you need at least 4A.

Yeah the 57 design was much better from this standpoint. Nothing to delam and if you keep the input voltage in check, they won't arc. Many of the modern rebuilders use far better materials than Quad did (and still do) use so with a fully rebuilt set of panels this is less of an issue.

I heard that DR used EMT as well and some ended up here. Never seen one though and the price... eek!!! Yup, they had quite a few ESL57's which were then all "rescued" by the engineers when they upgraded. With QuadII's or 303 amps they probably worked great for years and years. My set is from 1968 and still on the original panels (refreshed electronics though) so it certainly can be done.

Now you need a DR one as well... The Swedes did have nice tastes back in the day with ESL57's as monitors and stuff like that.

Standard setup is to connect pin 3 to pin 1. On my amps everything is grounded together so that way works perfectly. The 252S works perfectly for them but they do scale up nicely. Used 313 or something like that?

It might be a bit anti climatic as I won't be doing a whole lot to it. Bend the arcs to suit my head and perhaps replace the foam inside the pads to the foam Kerry made.

Gotta love the magic smoke...

The 007's really need a kick up the backside to perform. I just got some 007BL's yesterday and they appear to be completely stock so it will be fun to modify them. Stock they sound just a bit dull to be honest. The bass has the slight overhang to it and the soundstage is a bit too big. Treble needs a slight kick up the pants but it can all be fixed with the arcs. Feels a bit like 2002 to me... when I was messing with the Mk1's for the first time.