Yep, thanks a lot 👍Correct, the SIT appears to have been the problem.
I luckily got 10 from a dubious source right when the original thread about the K2087C started here. They were obviously pulls from older equipment.
I didn’t spend a lot, and ended up with two pair that have worked for me. Two other lucky forum members got a pair of K2087Cs from me.![]()
Apologies for going off script, but I changed out the SIT in the errant channel.
Biased up fine. Cooking in now with ~ 180mV across R141. DC offset drifting around less than 10mV.
Woo hoo!
swell!
that was exactly next step I had on mind - checking/replacing OS parts
!!

(TDV is good, but no direct comparison possible)
Starting now! I’ll let you all know.
(Edit: the hum is gone while connected in the main system)
and, how it sounds in Big System?
FABulous! I am enjoying it very much!
I would say that it produces a more detailed sound than the TDV, which I expected due to the distortion profiles shared by you for Scryer and codyt for TDV.
I heard new things in a couple familiar songs earlier today. That’s always a good sign. 😎
Another win from Zen Mod Labs! Thanks again for the design, boards, kit, and support! I like this amp VERY much. I’d say it’s the happiest medium in presentation between the velvety VFet Lottery amp and the clinical F5 (and I LOVE those amps).
I would say that it produces a more detailed sound than the TDV, which I expected due to the distortion profiles shared by you for Scryer and codyt for TDV.
I heard new things in a couple familiar songs earlier today. That’s always a good sign. 😎
Another win from Zen Mod Labs! Thanks again for the design, boards, kit, and support! I like this amp VERY much. I’d say it’s the happiest medium in presentation between the velvety VFet Lottery amp and the clinical F5 (and I LOVE those amps).

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After a few days, the Scryer is doing marvelously well. I have babysitter fans quietly blowing directly onto the chassis sinks so they are just slightly warmer than ambient (they’re 4U 300 from the Store).
A moment ago I tweaked the Iq on one board for a few mV back up to 180mV and adjusted the DC offset back to less than 10mV.
My initial subjective review holds. It’s a lovely sounding machine.
A moment ago I tweaked the Iq on one board for a few mV back up to 180mV and adjusted the DC offset back to less than 10mV.
My initial subjective review holds. It’s a lovely sounding machine.

Something else I really like about Scryer - it’s got Jfet, BJT, SIT and MOS all represented in the signal path. I’m sure that’s not as uncommon as I think, but either way, it’s a cool foot note.
Yeah, I always thought, it is not so important what parts you use for a good amplifier, but how.
I think, it is inevitable for me to build one. (or two)
As the latest news, Scryer equal to Oracle, so it certainly will know the winning lottery numbers as well.
I think, it is inevitable for me to build one. (or two)
As the latest news, Scryer equal to Oracle, so it certainly will know the winning lottery numbers as well.
Same. I would think it would sound at least somewhat like a Scryer big brother. Maybe ZM knows…. 🙂
Could take a few weeks, I'm working on bothSo many choices from Mighty ZM. I love what's operating in my rack from Aleksandar.(SissySIT42, XA252 big puck, SB)
I would like to hear a Scryer XA252 SIT comparison - anybody? 😊😊😊

Same. I would think it would sound at least somewhat like a Scryer big brother. Maybe ZM knows…. 🙂
I already told ya - all my amps are sounding the same
I mean, there is such technical limit to express sincerest form of flattery (to Pa, whom else) so in time I got asymptotic to plateau of my cloning abilities
If nothing else, I discovered beauty of naming each of them differently, so avoiding calling them "DIY iteration of xxx Papamp"

So, the only obstacle to bring out new amps is the lack of new names?I already told ya - all my amps are sounding the same
I mean, there is such technical limit to express sincerest form of flattery (to Pa, whom else) so in time I got asymptotic to plateau of my cloning abilities
If nothing else, I discovered beauty of naming each of them differently, so avoiding calling them "DIY iteration of xxx Papamp"
![]()



I'm having bigger list of names than number of finished projects on paper than number of projects finished in vivo
So, still perfect ratio
So, still perfect ratio
I am curious how SB compares to a DEF amp. Is there already a write-up somewhere?SissySIT42, XA252 big puck, SB
To my ears with Iron Pumpkin and Tannoys.
Currently I listen to the SissySit 42 70% of the time, the XA252 (big puck) 20% and the Singing Bush 10%
The SissySit42 and its predecessor in my system the SissySIT ver 1 are more involving. They make you want to tap your feet and just enjoy the music. The big puck 252 may have a bit more detail but lacks the SIT magic and even though the SB is a great SIT amp I don't need 50plus watts.
All have enough detail for me. It's about the magi - the feeling I get when listening I do have a Old Soul and a LuDEF ready for a case and I do have an interest in a Scyer and the XA252 SIT. I have heard the XA25 many times and it is a great amp.
Currently I listen to the SissySit 42 70% of the time, the XA252 (big puck) 20% and the Singing Bush 10%
The SissySit42 and its predecessor in my system the SissySIT ver 1 are more involving. They make you want to tap your feet and just enjoy the music. The big puck 252 may have a bit more detail but lacks the SIT magic and even though the SB is a great SIT amp I don't need 50plus watts.
All have enough detail for me. It's about the magi - the feeling I get when listening I do have a Old Soul and a LuDEF ready for a case and I do have an interest in a Scyer and the XA252 SIT. I have heard the XA25 many times and it is a great amp.
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