Anyone out there still using Counterpoint SA4?

I had SA4 bought from Sun wah before, around 12 years ago, difficult to find good power tube , 6LF6, dc offset of SA4 sometime could be fussy,Very Dynamic and good transparency but bass is not very articulate. Afterwards I bought a pair of ARC classic 150 to relace SA4.

Now I use BAT VK150SE, much more powerful and solid bass and great transparency, and 6c33c is much easier to find, the most important thing is that VK150SE does not use NFB (zero NFB) where counterpoint SA4 rely on high amount of NFB to achieve low output impedence to drive speaker

My impression is my current VK150se using opt transformer is even faster and clearer than SA4 (due to zero NFB on VK150se)


最後修改時間: 2018-07-01 00:11:03

I also do not think many SA4 are still in operation nowaday because of lacking of power tube supply and their famous IC stored bais control creating so much stability problem

Having said that counterpoint SA4 is legendary, comparable to NYAL OTL amp, but you have to get rid of its IC bais circuit by subsituing individual tube bais control, Micheal Eiliot did that for SA4 user in his later Alivista workshop, but he has retired

最後修改時間: 2018-07-01 00:42:18

There is different version of SA4, issues was caused 90% heat problem that impact those ICs., as long you have luck to get the latest one (serial numbers after 9Xxx, boards/caps/Transformer are vary) and give more than enough sufficient space for heat dispersion, SA4 definitely is one of the amp (solid state or tube) that can compete nowadays any hi end gears at any prices in terms of speed, definition, sound stage, etc

I recently acquired a very good condition of SA4 and purchased 2 sets brand new 6FL6 tubes for spare, I’m so surprised how the sound of these beast that beat many of amp I used before,

Where did you get the brand new 6LF6, 6LF6 has become rare item because some Futterman amp also use them and Futterman amp is now collection item seen by many such that a lot of user have bought up all new 6LF6
I once bought a set of so called brand new 6LF6 from ebay but in fact they were not brand new

The one I had was with Wondercap coupling cap but I do not recall the SN no.

Also driving 4 ohm speaker (like Wilson) with SA4 give you only 60 watt of output power

最後修改時間: 2018-07-01 11:27:39

Completely new with all the data paper.
I’m not a technical guy on talking power/impedance, what I found the SA4 is even slightly more powerful than my previous Cello Performance / Counterpoint NPMA, it is the fact, hearing is believing.

Did you buy the 220V version SA4? In fact a friend of mine has been also searching for SA4 at 220V but no luck so far

最後修改時間: 2018-07-01 13:25:23

I have the schematic to install separate bias control on SA4. Anyone interest can pm me.