[samplesj]

Ooops, I'm afraid I didn't look closely enough at my next amp project.

I've only seriously (long term) run 2 different amps with it and they were both 100k input impedance. 

I just realized that it only has a 27k input impedance.  Since the Clarinet has a 3k output impedance I'm not going to hit the 10x goal with my new amp.

I'll need around 1.5v for full output.  For a short cable (1m) will this pose any "real"/audible (or even under 40khz) issues or is it just a problem if I ever go longer.

If the cable construction matters it is unshielded palladium with eichmann bullets.

Obviously when I finish the amp and listen I'll know for sure, but since its not done yet I still have a change to make changes if its going to roll off too early.

[hagtech]

The combination will definately work.  The question is how much degradation will there be, if any.  The 10x is just a crude rule of thumb, nothing magical.  Cable or length will not be a factor (except for the usual sonic differences).  I think the worry is if there will be any compression using the 27k loading.

jh

[samplesj]

The combination will definately work.  The question is how much degradation will there be, if any.  The 10x is just a crude rule of thumb, nothing magical.  Cable or length will not be a factor (except for the usual sonic differences).  I think the worry is if there will be any compression using the 27k loading.

jh

Sorry I'm not sure I understand.

What do you mean by compression?  High frequency roll off? 

How does the Clarinet do when asked for higher than normal current?  Will that push the tubes past their recommended operating limits?  Is that what you mean by compression, that I'll be pushing the tubes into distortion?

[hagtech]

There won't be any frequency rolloff.  Ok, ok, maybe you'll suck it down from 100kHz to 90kHz with a long cable. 

The 27k load will drop the level 1dB.  On a scope it will look perfectly normal.  However, sonically you might hear a slight loss of dynamics.  A tiny bit of headroom compression.  Nothing you can measure easily.  Second order harmonics should start coming up.  This is just the direction the sound will tend towards, which is easy to test by loading with 3k.  At 50k there is no loss.  At 3k you can hear it.  At 27k I'm not sure, never checked.  The change is gradual and I don't know exactly where it begins.  Most likely you are safe.  I'm sure many readers will be interested to hear your report back.

As far as overloading tubes, that would be a combination of signal swing and impedance.  The stage operates at 5mA or 6mA (I forget).  So a 2Vrms output (2.8V peak) into a 600 ohm load would be at the edge of clipping on negative going swing. 

jh