[KDS315]

hello
thank you for reading my post,



i own a stax amp SRM T 1, and i would like to change the valves, any recomendation, as proper valves to use, i have seen rca, ge,...

these are , GE 6FQ7 / 6CG7

sellers ?

any tricks on. what to do, and how to do it ? regards

i made a search about valve replacement and found nothing

thank you

IF you want to do that, consider having CCS (constant current source) installed instead of anode resistors, this has much greater impact as you get much more audible energy. PLus there is the possibility to use ECC99 valves but needs a few modifications. I had both done here in Germany at Stritt-Audio Freiburg and the results are amazing, my SRM-T1 (CCS/ECC99) even drives a SR-007 well now!!

 

[kzs70]

IF you want to do that, consider having CCS (constant current source) installed instead of anode resistors, this has much greater impact as you get much more audible energy. PLus there is the possibility to use ECC99 valves but needs a few modifications. I had both done here in Germany at Stritt-Audio Freiburg and the results are amazing, my SRM-T1 (CCS/ECC99) even drives a SR-007 well now!!

Hopefully mine arrives tomorrow, I look forward trying it with my 009
Do you use the new JJ gold tubes or perhaps other NOS tubes?

 

[oximoron]

IF you want to do that, consider having CCS (constant current source) installed instead of anode resistors, this has much greater impact as you get much more audible energy. PLus there is the possibility to use ECC99 valves but needs a few modifications. I had both done here in Germany at Stritt-Audio Freiburg and the results are amazing, my SRM-T1 (CCS/ECC99) even drives a SR-007 well now!!

thank you, i note that for a next future
right now i would love to simply put fresh valves on, and check the difference
i have never done that before
so again,

GE, or Sylvania, or RCA, or other ?
were the original ones GE ? i think so as per pictures
where to buy, buy NOS ? or it does not make any difference ?

how to do it, danger, danger , high voltage, but what is exactly the problem, i know about capacitors, but i will only remove the tubes, and put new ones

thank you

 

[dynavit]

If you change tubes, you have to adjust the bias again, because the TRM 1 is not self-biasing. It is not a miracle to do this, but you have to work on an opened amp with high voltages.
I am not a technician and have done it once on a 007t with instructions from the web and it worked, but I have to warn you.

 

[KDS315]

You will still have to open it and while on and under high voltage adjust the balancing potentiometers with new tubes using a voktage meter? Are you ready for DOING THAT?

EVEN A BALANCED SET NEEDS THAT ADJUSTMENT!!

 

[dynavit]

You will still have to open it and while on and under high voltage adjust the balancing potentiometers with new tubes using a voktage meter? Are you ready for DOING THAT?

EVEN A BALANCED SET NEEDS THAT ADJUSTMENT!!

Seems we had the same thoughts at the same time!

 

[oximoron]

You will still have to open it and while on and under high voltage adjust the balancing potentiometers with new tubes using a voktage meter? Are you ready for DOING THAT?

EVEN A BALANCED SET NEEDS THAT ADJUSTMENT!!

i appreciate your warning advice, very much indeed, i am prepared yes, i assume that it is doable once taken certain precautions

(i fix everything on my own, i always get in high esteem others advice, and try to follow all the rules, specially safety, ...i feel anything that you repare by yourself provides you double satisfaction)

 

[oximoron]

If you change tubes, you have to adjust the bias again, because the TRM 1 is not self-biasing. It is not a miracle to do this, but you have to work on an opened amp with high voltages.
I am not a technician and have done it once on a 007t with instructions from the web and it worked, but I have to warn you.

thank you
your example helps and encourages me !

 

[oximoron]

so GE tubes might be the right stuff ?
any link to the process ?
any source for these tubes ?

 

[dynavit]

so GE tubes might be the right stuff ?
any link to the process ?
any source for these tubes ?

Try this one, but there are more: https://www.head-fi.org/articles/adjusting-bias-on-stax-tube-amplifiers.17232/

 

[martin778]

Its easy to do albeit a bit tedious as the trimpots are always very sensitive and even blowing against the circuit board will make the readout jump around. I always prefer measuring with the lid closed.
Just make sure not to use a screwdriver with metal grip

 

[AthenaZephyrian]

I've had an SRM-1 Mk2 Pro for about 4 years and it has served me and my L300s well but I recently acquired a pair of Nectar Hives, which I have heard scale quite well. I know the SRM-1 Mk2 Pro (while the best I could afford when I purchased it for $500) is only just barely a fair-to-midlands amp in the grand scheme of estat amplification. I would buy a KGSSHV Carbon if I had the money. If I had a good set of machine tools, I'd build one but I lack a milling machine to manufacture a suitable enclosure. Thus, I'm looking at buying a used KGSS for a bit under $1k. From what little I can see, it was, at least at one time, regarded as better than most/all STAX-made energizers/amplifiers. Is this still the case (or, at least, better than all those that are not many times its price)?

 

[padam]

I've had an SRM-1 Mk2 Pro for about 4 years and it has served me and my L300s well but I recently acquired a pair of Nectar Hives, which I have heard scale quite well. I know the SRM-1 Mk2 Pro (while the best I could afford when I purchased it for $500) is only just barely a fair-to-midlands amp in the grand scheme of estat amplification. I would buy a KGSSHV Carbon if I had the money. If I had a good set of machine tools, I'd build one but I lack a milling machine to manufacture a suitable enclosure. Thus, I'm looking at buying a used KGSS for a bit under $1k. From what little I can see, it was, at least at one time, regarded as better than most/all STAX-made energizers/amplifiers. Is this still the case (or, at least, better than all those that are not many times its price)?

It's better in terms of the power supply and different parts being used, but it's not necessarily better in terms of sound and it is a little difficult to take a stance without knowing how it interacts with that particular set of headphones.
So oversimplified goes like this: if you want to be close to the warmer, more diffused nature of the Stax amp, get a 717 or a modded 727 (which has CCS unlike the other two). If you prefer it to be more focused and more neutral, get a KGSS.
Old quote:
"The 717 has a more laid back sound (especially in the midrange) than the KGSS. The 717 has a considerably larger soundstage and does a better job of creating the environment of large acoustic recordings. I think that people that listen to a lot of Pop music with typical flat presentation may like the KGSS better. When you listen to the 717 you hear delicate low level details and ambiance that the KGSS seems to mask. One time when I was listening to the KGSS I thought I had my preamp in mono but it wasn’t. I have been extremely happy with the 717/SR-007 combo. Sometimes I can’t seem to leave well enough alone"
Old review:
https://positive-feedback.com/Issue12/staxomega.htm
"I was desperate to hear the Omega IIs with a different amp, especially one that sells for approximately the same price as the 717, to isolate their character. Surprisingly, the incredible extremes, the lack of identifiable sound, the resolution, and the transient response stayed constant. All this I give to the Omega IIs, yet the two amps sound drastically different. The KGSS eliminated most of my midbass complaints. It sounded dramatically blacker and more linear than the 717. Resolution wasn’t better, but the KGSS allowed details to pop in the digital black and fade away quickly. Stereolab’s ABC Music sounded like heaven. Bass guitar wasn’t as diffused as it was with the 717. The presentation was tighter, and the sound closer to what I expect from headphones as opposed to speakers. The Omega IIs with the 717 have an expansive soundstage, in which performers take another step back. The 717’s reproduction of acoustics will make it the choice for many. I’d take the KGSS, but you already know my bias."

 

[AthenaZephyrian]

Well, I missed my chance on the KGSS. I'll have to keep looking! Interesting info, though, and I think it's still quite informative in my search for a better amp. I may have to try one of the two you mentioned. I do like my large soundstages...

 

[musicman59]

https://github.com/jaakkopasanen/AutoEq/tree/master/results/oratory1990/harman_over-ear_2018

Thanks for the link. I use Room but I have no idea how to apply these filters.
If you can PM me some instructions I will really appreciate it….