[Lkdog]

I am trying to find out if anyone has had issues with their tube preamp output impedance and their Stratos amp.
It is my understanding that the redboard Stratos models have an input impedance of 10K-11K ohms.

My tube preamp has an output impedance of 2k Ohms-3K ohms per the manufacturer. An end user I talked to states he thought it was actually around 1k-1.2K ohms. Maybe the measurements were taken differently.
It is an Audio Mirror PP1.  He states his PP1 works fine with his Stratos Extremes.

The manufacturer thinks that the PP1 will work fine with the Stratos Dual Monos I am getting.

I know the 10:1 ratio is suggested for AMP/PREAMP. This would be more like 5:1 or 3.3:1 even.
Others say this is just one factor and other factors determine if there is actually a mismatch that impacts the sonics.
The preamp specs are:

Frequency response 10-58000hz
T.H.D. 0.1%
Line gain 15dB
Phono Gain
MM 41dB
MC 61dB
Noise:
Line better than 90dB
MM better than 85dB
MC better than 79dB
Output Level 3 volt (full gain)
Input Impedance 47 K
MC selectable from 250 ohm to 2.7K


I have done searches here and have not found anyone who states they have had an issue with any tube preamps.
In fact people state that the Stratos is "tube friendly" with a wide range of tube preamps.

I have also seen where someone stated that the new Candela had an output impedance of 2Kohms and works great, of course, with Stratos amps.

Any user feedback is welcome. I have an email into Klaus, but was interested to know what people here had to say.
Thanks.

Oh, when I do get my Dual Monos-how will I actually know if there is an issue? Sort of an Alice in Wonderland paradox.
How do I know if I am not hearing something (high end or bass roll off) if it is not there.
Would it be that noticebale?

Thanks.

[dgotlse]

I faced the same kind of issue : I was told by Jean Hiraga of "French Revue du Son" that a "more than optimal" ratio between preamp and amp will not damage any of them,but might bring some distorsion on the higher frequences and some kind of roll off.

As far as you don't use huge lengths for interconnects, you won't get any trouble with your set. 

[Lkdog]

Bonjour-

Did you mean to say that even if it is "less than optimal" ratio it should not cause any problems?

I will be using standard 1 meter IC's.

[DMi]

I do not think that you are going to run into any issues unless you're using long runs of interconnects or very high impedance cables from the pre-amp to the amplifier. I have not used a tube pre-amp but I have had long runs between them and violated a few rules regarding high capacitance cables and all I noted was a roll off and some additional grain on the highs with a Stratos Stereo Plus using the older non-red board configuration. I believe the input was around 10k and that should be high enough to not cause you sonic issues.

With one meter interconnects I doubt you're going to see an issue.

Doug

[bunky]

I am trying to find out if anyone has had issues with their tube preamp output impedance and their Stratos amp.
It is my understanding that the redboard Stratos models have an input impedance of 10K-11K ohms.

My tube preamp has an output impedance of 2k Ohms-3K ohms per the manufacturer. An end user I talked to states he thought it was actually around 1k-1.2K ohms. Maybe the measurements were taken differently.
It is an Audio Mirror PP1.  He states his PP1 works fine with his Stratos Extremes.

The manufacturer thinks that the PP1 will work fine with the Stratos Dual Monos I am getting.

I know the 10:1 ratio is suggested for AMP/PREAMP. This would be more like 5:1 or 3.3:1 even.
Others say this is just one factor and other factors determine if there is actually a mismatch that impacts the sonics.
The preamp specs are:

Frequency response 10-58000hz
T.H.D. 0.1%
Line gain 15dB
Phono Gain
MM 41dB
MC 61dB
Noise:
Line better than 90dB
MM better than 85dB
MC better than 79dB
Output Level 3 volt (full gain)
Input Impedance 47 K
MC selectable from 250 ohm to 2.7K


I have done searches here and have not found anyone who states they have had an issue with any tube preamps.
In fact people state that the Stratos is "tube friendly" with a wide range of tube preamps.

I have also seen where someone stated that the new Candela had an output impedance of 2Kohms and works great, of course, with Stratos amps.

Any user feedback is welcome. I have an email into Klaus, but was interested to know what people here had to say.
Thanks.

Oh, when I do get my Dual Monos-how will I actually know if there is an issue? Sort of an Alice in Wonderland paradox.
How do I know if I am not hearing something (high end or bass roll off) if it is not there.
Would it be that noticebale?

Thanks.

A few folks from this forum with Odyssey's newer Red Board poweramplifiers have tested the output impedence at 17 to 18K ohms. i am on my third tube preamplifer using Odyssey power amplifiers and i have had Zero compatability issues.Enjoy....WCW III

[Lkdog]

A few folks from this forum with Odyssey's newer Red Board poweramplifiers have tested the output impedence at 17 to 18K ohms. i am on my third tube preamplifer using Odyssey power amplifiers and i have had Zero compatability issues.

Maybe I am recalling the specs wrong. I thought the older greenboards tested by users were 17-18K ohms input impedance, and the newer redboard ones were around 10K-11K ohms.

Good to hear you have had no issues.

I see you have a Candela. I read somebody here stated the output impedance is 2k ohms.
Is that your understanding?

What other tube preamps have you tried?

Thanks.

[bunky]

A few folks from this forum with Odyssey's newer Red Board poweramplifiers have tested the output impedence at 17 to 18K ohms. i am on my third tube preamplifer using Odyssey power amplifiers and i have had Zero compatability issues.

Maybe I am recalling the specs wrong. I thought the older greenboards tested by users were 17-18K ohms input impedance, and the newer redboard ones were around 10K-11K ohms.

Good to hear you have had no issues.

I see you have a Candela. I read somebody here stated the output impedance is 2k ohms.
Is that your understanding?

What other tube preamps have you tried?

Thanks.

The Candela's output impedence is 2K ohms as per the spec sheet that Klaus sent with my Candela.i have a Anthem Pre1L and a Balanced Audio Technology VK 3i and they all work perfectly with my Odyssey monoblock's. the Candela is the best sounding tube preamplifier that i have ever heard and that includes the very popular Giant killer Modwright tube preamplifier as well.the Candela is stellar in my two channel rig.thanks....WCW III  

[Lkdog]

Bunky- Thanks.
I had a chance to talk to Klaus today.
He also feels that the PP1 should be fine and confirmed that the Candela had a similar output impedance.

He stated that he was not aware of any impedance matching issues with the Stratos amps due to their gain.
I am not sure exactly what that means, but that is reassuring that he has not had anybody call him with issues as he has
thousands of units out there I am sure.

I will know for sure in January when I get my Dual Monos.