Stitch wrote:

TKD has also high quality Parts which are not listed in the catalogue. I heard, some personal contact can be helpful to get their best units. They will be built on custom order only, in batches, when they made it, it is done. Price, well, when you have to ask ....

N-set wrote:

This is EXACTLY the bullshit I wanted to avoid and never touch...hermetical circles...special orders...dick sucking....fuck off! As I understand you are not able to comment on the switch nor on its performance in your radar? It is also not about price--but about performance for a given price. I'd pay 200Eu for a switch knowing it's up to the task and this "up" will last substancial time. IN this situation of lack of information---lost money. I can make you a switch out of unobtanium-suck-my-dickium for 20000 Eu, so what? If nobody knows if it switches well or not apart from a closed circle of a few who did suck my cock and said it was tasty?

Romy the Cat wrote:

In the end of everything I was able to get very nice response. The response is nice and flat with 0dB at 18.1Hz and 0dB at 15.600Hz. It has plus 0.2dB from 1500 to 3500 which I feel is not a big deal. (Juts for my future reference: the values of the feedback capacitors have without de-soldering capS from the circuit are: 110pF= 136.2pF and 330pF=372pF)

This level of calibration is something I can dream of, as well as of this one (Fig. 1):

http://www.stereophile.com/content/ear-834p-phono-preamplifier-measurements

I have a massive +2.2dB  peak around 35-50Hz. No matter what I do it's there, getting broader or narrower and slightly moving.

From 1kHz up I can flatten the things out very nicely. I scan the phono using (HF corrected) Hagtech iRIAA.

Since Jim mentions it wants to see 50R source, I've been driving it with 50R out of Tek SG505 generator

or with my sound card with unknown output R....all gives the same. I somehow start to suspect that I have

some circuit problem. I tried to measure aircaps in the circuit but my simple C-meter gets crazy and prefer not to desolder them

unless necessary. The big cap responsible for LF looks actually identical to Romy's and should give up to 390pF, so plenty of room.

Anyone have any idea what the heck may be wrong? Where does a ~50Hz low Q peak may come from?

Any help appreciated. Thanks,

N-set

PS There is one circuit change wrt the original: I use 1uF instead of 2uF output coupling cap.

Romy the Cat wrote:

Yes, this is what I expected. That slightly fatty lower range is what I have and I do tend to like this type of response.

Paul S wrote:

N-set, you've certainly earned the right to enjoy your gear!  Again, which SUT will you use? No practical way to measure ESR, etc. on this, I suppose...