Bottlehead Forum

Bottlehead Finished Products => Stat Electrostatic Headphone Amplifier => Topic started by: Doc B. on September 14, 2020, 10:58:01 AM

Title: Our new ES headphone amp
Post by: Doc B. on September 14, 2020, 10:58:01 AM
Made to order. Check it out - (
Title: Re: Our new ES headphone amp
Post by: bigjako on May 02, 2021, 09:14:23 AM
I bought the blue Stat secondhand a couple months ago, and it got trashed pretty bad in shipping (the seller did not package it well).  Fortunately, Paul helped me out and now I'm the proud and eager owner of a functioning, beautiful Stat amp.  I have this setup right next to a CCS-modded SRM-006t and I'm looking forward to tube-rolling the Stat and comparing them.  To that end, I have a couple questions to help me (and I think other owners) with that:

1. On the Product page, it references the 'first diff amp' and 'second diff amp' but I'm not sure which is which.  Is the 'first' the socket pair in the back or the front?

It also says that the first diff amp can roll a whole bunch of tubes, and that the second diff amp is less so.  In all my readings, I've heard that the 2nd diff amp choices are between 12BH7 (bandwidth) or 5965 (gain) but the product page also says that 6SN7s are usable with adapters.  So the questions are:
2. Can I also use the 6SN7s (with adapters) in the first diff amp too?  The product page doesn't list the 6SN7s in the long list of acceptable tubes, though it does for the more restrictive second diff amp. I already have some 6SN7s and would like to be able to try them out.
3. Am I correct that the adapter I want to buy is the one that "Converts a 6SN7 tube to a 12AU7 socket."?
4. That same adapter also says "Your device must be configured to use the center tap of a 12AU7 tube and run at 6.3V to work properly - Please confirm with your manufacturer that your amplifier is configured this way." - I can't find any reference to whether it a) uses the center tap and b) runs at 6.3V. 
The adapter I'm referring to is Option 2 on the other site.

And yes, the last question is whether the Stat will "properly" drive a SR-007.  I don't have one, I have 3 different Lambdas and they're easy enough to drive (in fact, I want to use 12BH7s because I can then crank the volume up, which I think is a good thing with estats).  I see that in the product announcement page, Doc says "The SR-007 says 100dB for 100V RMS.  This amp can do close to 600V peak to peak, which is over 200V RMS, so yes, output shouldn't be a problem." but I asked a electrostatic manufacturer about it and he said "the unmodded T1 can do a 846v p2p voltage swing (official 300vrms data*1.41*2=846v p2p) so the 600v on your bottlehead seems to be a bit limited."  I didn't buy the Stat for 007s, and I suspect the answer will only come from a 007 owner who has a 3rd party amp to compare to, but I'm curious if any existing Omega owners have run 007s or 009s from it.

Thanks for any help you can provide!
Title: Re: Our new ES headphone amp
Post by: Paul Birkeland on May 02, 2021, 01:04:54 PM
I e-mailed a copy of the manual over to you that goes through this in great detail.

Title: Re: Our new ES headphone amp
Post by: bigjako on May 02, 2021, 01:32:19 PM
Thanks Paul, you're right - it wasn't included by the seller, but that answered all my questions.