Tube advice needed

[ben62670]

OK I built my tube grounded grid pre, and I am having a minor issue. It plays fine when I turn it up, but when the volume is real low it distorts. The heaters are 12.16vdc regulated. This is almost a half volt low. Is this a concern? Also the output impedance is 100k is this too high?
Thanks
Ben

[GV#27]

Also the output impedance is 100k is this too high?
Yes big time:eek:Is there a 100k pot at the output?

[ben62670]

Oops input impedance on my pot. For testing purposes I have the pot after the pre.

[GV#27]

I would connect a pot of that value at the input side.

[ben62670]

I will, but right now I am in testing phase. I have a lot of work to get everything in one case. The tube/passive/active pre with a DAC and an XO is almost complete:) Very very happy here:):):)
I bought an Adcom surround pre for the case to stuff this stuff inside. I want the tubes sticking out the top. The only clue that it isn't an old POC surround processor;)

[ben62670]

I so wish you could hear it. The snap of the drums, and the rim shots are freaken fantastic! Seriously if you ever are down stop and stay!

[GV#27]

I so wish you could hear it. The snap of the drums, and the rim shots are freaken fantastic!Good to hear your liking it.You might want to try a stepped attenuator instead of the pot.
I recently replaced the Alps in my pre with a 20k Valab series stepped att .It is an Asian sourced clone of the megabuck DACT unit's and built to a high standard ( sells for a mere $20 ish epay).Compared to the Alps it has perfect channel balance regardless of setting,increased detail was apparent and the noise floor was lowered.IMO an inexpensive but very worthwhile upgrade/tweak.

I may get another for the direct coupled Pass B1 I'm building.


Seriously if you ever are down stop and stay!Thanks for the offer,though the temp's that far south might be too hot for us igloo dweller types to handle.