spritzer

Is there no direct ground connection from the sockets to the pot? Conduction in those boxes is shit unless you take special measures to get good contacts all over the place. First thing I'd try... I've used one Toroidy transformer and it worked well enough but who in their right mind puts 10cm leads on transformers?

LNS drivers in a HE90 shell sounds very nice indeed...

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Twisting or braiding AC disrupts the magnetic field so it's a good idea. With DC it's not crucial and could even be a bad idea (capacitance)

Indeed....

I'm with Doug that simply adding series resistance to transformer coupled amps is not a good idea but with directly coupled amps it works just fine. I do think the HD800 first and foremost needs a very stable amp, one that isn't swayed by the odd load. Take something like the SPL Phonitor, arguably wire with gain but really just a crappy opamp circuit and it sounds horrible with the 800. Thin, bright, edgy etc. and adding 32 ohm to it (it's output impedance is 9 ohm) didn't make it right. Better but not as good as the Dynalo or Dynahi with the same 43ohm. OTL amps have their own issues too. In the HDVD800 I think I can make out 22R in series with the SE outputs and 10R in series with each leg of the XLR. I wonder what output chips they used though... Couple of things I like about the L-2, the glow is all but impossible to see and there is no tuberolling.

It is a bit ironic that the most revealing dynamic headphone ever made needs that... I'm with Ari though that wire with gain is not a good thing for the 800's at least not fully stock.

Interested about the transformer too as I'm looking at other options. The Asia suppliers usually fail to be cheap once I impose strict tolerances and specs such as low max heat rise. They usually underspec the cores and use silly small wires to keep the cost down. I did contact Talema as they are so close to me in Ireland but haven't heard back.

Don't get me started on front panel today. My laser guy decided go cheap and only placed the color film on the spots that were going to be marked. It's pretty much silkscreen by laser but then he has to submerge it in a solution to clean it all off. That solution oxidized the panels but only where there was nothing to cover them so hello patchy panels. Time to find somebody else to do this... As for the volume knob guide pin, just cut it off. No need for it if you can secure the pot properly.

http://soundnews.ro/2013/07/18/sennheiser-hdvd800-review/ Internal pics and it is quite dire indeed. Chipamps underneath the big sink and hello output resistors which means the 43ohm was intentional.

I'd go for it. The 207 is just lovely if a shade bright but nothing like the Pro's.

The B22 would be a pretty terrible match for the HD800 in the first place. It's certainly not fully neutral with a tendency towards brightness which is not a good match. I do get somebody liking the Rudistor as the cap coupled output and quite frankly, horrific circuit design would fix some of the HD800's issues. Now this is doing it with a nuke than a tactical strike but the end result could be pleasing. People sure like the Luxman amps with the HD800 and the circuits have some similarities, including the cap coupling.

The comparison is against a Rudistor... I'd think severe brain trauma could be a factor here.

They really need to have the correct bias voltage, +500V and 10M. It just so happens you have a nicely regulated +500V in there already. Just take a line from there with a small 10nf bypass cap and a 10M resistor to the Fischer socket. One thing to note, the HE90 should never see more than 1000Vp-p at any time which the HV will easily pass even with a 2V source.

Looks good. I was going to finish 3 HV's over the weekend but my laser shop fucked up 2 out of the 3 front panels...

No but the Squarewave would be a good alternative.

That looks ok and the tube sockets are the CMC teflon units (or the ceramic ones would probably work) and the terminal blocks are just the standard 0.2" pitch. Here is how far mine has gone. Almost took off my hand with that bloody drillpress so this is on hold while I make a few KGSSHV's.

No issues here except them always being perfect. That might annoy some people...

The 350mm Modushop Slim boxes will work just fine. Maybe even a bit too big but we'll know next week when I'll fit the boards into one of those.

Could very well be that I've got it backwards as dynamics really aren't "my thing". The opposite is certainly true for electrostatics but then again we are worlds apart there in almost every aspect of transducer behavior. The damping factor would actually be higher since the impedance is often quite a bit higher than 300R according to the Headroom graph. Edit: Won't allow me to attach pnp's so here is the link: http://graphs.headphone.com/graphCompare.php?graphType=7&graphID[]=2321&scale=5 Very odd curve to say the least...

It's a transformer based input so the amp doesn't care if it is XLR or RCA input. Just use a normal XLR-RCA adapter and it will work just fine.

Output impedance=damping factor so yeah, it is a huge factor. With speakers and their often highly complicated crossovers it can be less of an issue but it indeed often overlooked.

Does anybody want to see what serial testing of KGSSHV boards looks like? That's the pile of fail from Hennyo all tested and working plus the new HVk (k for kompakt) boards verified working. I still have to test the servo but I forgot to order the caps... The new input fet didn't work for me but it was probably my soldering. It's tiny... to say the least.

Something being unsoldered is just lucky. I haven't looked at mine for months now, plenty of other headaches to deal with...

Nope, after changing all the sand more than once the problem still remains. The only plausible explanation for this behavior has to be the K216 on top of the batteries and I was waiting on some old K216's because the recent units may not work as it should. It is a long shot but everything tests ok. After this I'm out of ideas and I'll have to take a trip to Chicago with the amp and bake Kevin a huge cake while he takes a look at it for me... Did something happen to your amp or did it power up like that for the first time? Mine did work and then the main CCS shorted to the chassis and it started to have problems.