[Ragnar71]

I know some of you use pre amps, just curious as to which pre amps have had good synergy with the cherry?

Also would like to know if anyone has Don Sachs Line Stage and how that is working out with the cherry

[MttBsh]

I use a Tortuga passive with my King STM, superb combination.

[Delta77]

A bit off subject,
I just received a switch box..
I wanted a remote volume control , and the ability to use my TT , CDP, and STREAMER, all without effecting the sound..
I’m already using a tube amp, so I didn’t want a tube preamp, just a straight signal with gain, and ability to switch to different sources...

Aric from Aric Audio made it for me..

[Ragnar71]

Declare makes one too.

[RichPark]

I am using a NuForce mcp18 for my Hypex Ncore N400. I have been using triode wire labs XLR.  These all work well together

[AvsFan]

I use a Tortuga passive with my King STM, superb combination.

Can you elaborate a little more? I have the 48v STM and I'm about to add the 60v power supply to make it a King STM. I have Tommy's DAC DAC 1HS as well. What makes the passive Tortuga such a superb combination? I've really been looking into pre amps. So confused as to wanting to go passive or active.

[MttBsh]

Can you elaborate a little more? I have the 48v STM and I'm about to add the 60v power supply to make it a King STM. I have Tommy's DAC DAC 1HS as well. What makes the passive Tortuga such a superb combination? I've really been looking into pre amps. So confused as to wanting to go passive or active.

I too have thought about the Don Sachs line stage and others like the LTA microZOTL, but I'm not sure they would provide much improvement, if any over the Tortuga passive. I've used a number of preamps in the past including Eastern Electric and Dodd but when I put the Tortuga in the system a few years ago it was a revelation, as in night and day... Clarity and resolution that I had never heard in a sound system. I had been thinking that adding tubes might flesh out the sound further, but when I added the King STM to my system a few weeks ago I was left wanting for nothing. Don't let the fact that the Tortuga is passive worry you, it has plenty of juice, and possibly a cleaner signal than an active preamp would generate. Tortuga announced a couple of weeks ago that they will be coming out with a new line of less expensive models (under a grand) that have all the sound benefits of their more expensive models but have cut costs in the enclosures. Those will supposedly be available later this month. You can try one out in your system and send it back if you don't like it.

There are other passives like the Luminous Audio Technology Axiom that cost about the same that may work just as well, maybe better, who knows? But for now I'm sticking with the Tortuga, combined with the King STM I have no real interest in listening to anything else.

[MttBsh]

I just read about the DAC DAC 3 https://www.audiocircle.com/index.php?topic=167508.msg1787186;topicseen#new which may become the best solution of all. Maybe your DAC DAC 1HS could be updated to include Tommy's built-in pre?

[MttBsh]

Oops.. NOT called the DAC DAC 3!

[celo]

What is the input sensitivity and impedance of the King/Standard STM? I thought they’re not suitable to use with passive pre, no?

[AmpDesigner333]

What is the input sensitivity and impedance of the King/Standard STM? I thought they’re not suitable to use with passive pre, no?

The STM’s gain is 16 (24dB).  Max out is 400Wpc into 4Ω with the 60V KING version of the STM.  400W into 4Ω is 40Vrms, so sensitivity is 40Vrms/16 or 2.5Vrms.  That’s at max volume.  KING and standard 48V versions have the same gain, but max power is 120Wpc for the 48V version.  So, sensitivity is 22.4Vrms/16 or 1.4Vrms.

Yes, the STM is suitable for use with a passive preamp.

[celo]

The STM’s gain is 16 (24dB).  Max out is 400Wpc into 4Ω with the 60V KING version of the STM.  400W into 4Ω is 40Vrms, so sensitivity is 40Vrms/16 or 2.5Vrms.  That’s at max volume.  KING and standard 48V versions have the same gain, but max power is 120Wpc for the 48V version.  So, sensitivity is 22.4Vrms/16 or 1.4Vrms.

Yes, the STM is suitable for use with a passive preamp.

Thanks. Isn’t the input impedance also important? I am just asking because that’s what I have read/been told. Not that I know why it is important.

[AmpDesigner333]

Thanks. Isn’t the input impedance also important? I am just asking because that’s what I have read/been told. Not that I know why it is important.

It's high enough at 40kΩ (balanced) not be an issue.

[celo]

It's high enough at 40kΩ (balanced) not be an issue.

Thanks! 40K ohms Even if I use the XLR-RCA adapter since I don’t have balanced preamp? Stupid question?

[dspringham]

I'm under the impression that the input Z in single-ended mode in only 10K. Would one need to be cautious of this lower Z when using input adapters and a single-ended source?

[AmpDesigner333]

Thanks! 40K ohms Even if I use the XLR-RCA adapter since I don’t have balanced preamp? Stupid question?

With the [provided] RCA adapters, it’s 20kΩ.

Even if the source resistance is high, the only effect will be attenuation, and very little, like 1dB. This attenuation is not frequency dependent if good cables are used (low capacitance). I say this to nip the “oh, then you should use these fancy cables” argument in the bud.

Fancy cables are not necessary, and won’t affect the sound unless they are not designed/built properly.  Ironically, the “fancier” the cable (expensive), the more chance they did something like using high capacitance wire, just so it will effect the sound, but the effect is negative!  I could go in about such things, but....

Also, the slight attenuation that might happen from sources with output impedance on the high side (including passive preamps) does not cause distortion, only attenuation.

[AmpDesigner333]

I'm under the impression that the input Z in single-ended mode in only 10K. Would one need to be cautious of this lower Z when using input adapters and a single-ended source?

The single ended input is 6.7kΩ and has 9dB higher gain to allow sources like high performance portable audio players to drive the STM to max output.  Such sources have lower voltage outputs.  However, distortion and noise from the front input is almost as low as the balanced input.

Regarding the effect of input impedance, see my previous comment.  Thanks.

[Tubeburner]

Back to your question about the Don Sachs preamp, the latest Sachs preamp trounced the Tortuga and about 15 other preamps I have owned. The Sachs preamp will never leave my home unless Don builds something better which would be an amazing feat. I do not have the cherry amps. Talk with Don about this and he will give it to you straight. The Don Sachs preamp is amazing and the most satisfying musical preamp IMO.