Valve Preamp with SS Power Amp

Hi Guys.

I'm currently auditioning a Quad QC Twenty Four Valve Pre Amp with my Quad QSP Solid Sate Power Amp.
Asking the question regarding matching I was assured that it would work ok, and it does. My concern is
that the volume control is a bit hot and it's sufficiently loud at approx 10 o'clock. I am aware that that the
impedance required for the preamp is around 50k ohms and the QSP is 15k ohms, which I guess is the reason
the volume control is hot.
My concern is; Is this doing any damage to anything and is it ultimately affecting fidelity.


Regards

When you say "the volume control is a bit hot", I assume you mean the knob itself.

If so, it's probably picking up a bit of radiated heat from the mains transformer which is right behind it, as can be seen in this photo:

http://i66.tinypic.com/2aj7rjo.jpg

Unless it's ridiculously hot, I'd not worry. As for the impedance match, if it sounds happy enough, I'd not worry about that either.

My knob gets hot as well and it pulses :eyebrows: :)

In this case I believe 'hot' means the control doesn't need to be turned far to get loud volume.

No problem other than convenience.

Quote:

---

Originally Posted by Audio Al

My knob gets hot as well and it pulses :eyebrows: :)

---

Well keep it away from mains transformers. :eek:

Quote:

---

Originally Posted by walpurgis

Well keep it away from mains transformers. :eek:

---

OK will do ;)

If as Dave says, it gets loud quite quick and its difficult to get several nice levels then i would walk away. It becomes a pain in butt. If its getting excessively warm i would also leave it as its not doing the carbon track any good

Quote:

---

Originally Posted by hifi_dave

In this case I believe 'hot' means the control doesn't need to be turned far to get loud volume.

No problem other than convenience.

---

I did wonder. :)

Sorry, didn't mean hot, as in temperature just it don't take a lot of turning from zero before it's load enough.
I guess from Daves' reply, no real problem then and it's not affecting fidelity

Quote:

---

Originally Posted by LittleTone

Hi Guys.

I'm currently auditioning a Quad QC Twenty Four Valve Pre Amp with my Quad QSP Solid Sate Power Amp.
Asking the question regarding matching I was assured that it would work ok, and it does. My concern is
that the volume control is a bit hot and it's sufficiently loud at approx 10 o'clock. I am aware that that the
impedance required for the preamp is around 50k ohms and the QSP is 15k ohms, which I guess is the reason
the volume control is hot.
My concern is; Is this doing any damage to anything and is it ultimately affecting fidelity.


Regards

---

It's because your preamp has too much gain for your power amp. It isn't going to damage anything.

You can try some in-line attenuators, like the Rothwell ones, which will give you a lot more volume control.