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My new to me Herron VTPH-2A - First impressions

Ok, so if you followed my other topic, you know I bought a used Herron VTPH-2A.  It came Monday night, and I've been listening for the past couple of days..

Being used, it didn't really need a break in, but I let it warm up for a couple hours just to be safe.

Ok, so there has been a lot of hype for this phono stage here on the forum.  I have one question.  Is it hype if it lives up to just about everything good that's been said about it?

Just comparing it to my current setup (CJ PV10a with phono stage and a SUT), running thru the CJ, it's a huge improvement.  I'll just talk in terms of musical timbre and extension here, acoustic instruments sound so much more right, and both bass and treble extension is much better.  No only is there more bass, but it's way better.  But the overall sound was still a bit soft.  Ok, so that was the CJ.

I switched over to the Bel Canto I recently got.  Sound was much better, but a little bit sterile, and the upper end was a bit harder than the CJ (not unexpected).

So I got a crazy idea.  I thought I'd see what the Herron would sound like piped directly into my power amp.  I did a little math, and some measuring of the Herron output to make sure it wouldn't overdrive or underdrive the amp's inputs, and it looked like a reasonable match.  Turns out it worked out great, it was at a very reasonable listening level.

Ok,  No upper range hardness, no softness, excellent, controlled extended bass.

Ok, so I think I have to rethink my preamp now.  Luckily, I can send back the Bel Canto (still during the trial period) and I guess I'll be looking at a new preamp.

I'll be bringing it over to a friend's house this weekend, where we'll compare it to a couple of different phono preamps he owns.
psychoticreaction

Showing 4 responses by lewm

lewm
13,511 posts
 
.Apologies. I did not see where you mentioned wanting a bit more gain. So go for it. I have no particular passion for passive preamplifiers by which of course I mean a buffer stage. 
lewm
13,511 posts
 
We don’t disagree one iota. The only issue is I misunderstood what you meant when you used the term passive preamplifier. Many people, myself included, would take that to mean a unit that has nothing in it but a volume control that can be implemented in any of several ways. The best of them use auto formers. Typically they do not need to be plugged in, unless they employ LED devices to illuminate the settings.But I know what you mean, and it’s a good idea in this case. And yet the OP has started another thread where he is searching for a line stage with gain. Go figure.
lewm
13,511 posts
 
If it is really "passive", then one must take into consideration the output impedance of the driving stage and the input impedance of the driven stage. In my own mind, "passive" means no active devices in the circuit. However, since it comes from First Watt (a la Nelson Pass, perhaps the best solid state designer we have) and since he calls it a "Buffer", I would guess it is an active device that adds no gain. If so, I agree it could be cool in this set-up.
EDIT.  I cheated and went to the website.  Indeed, this is a buffer, not passive.  Here is what Nelson Pass wrote:"This suggests the possibility of using a high quality buffer in conjunction with a volume control. A buffer is still an active circuit using tubes or transistors, but it has no voltage gain – it only interposes itself to make a low impedance into a high impedance, or vice versa.

If you put a buffer in front of a volume control, the control’s low impedance looks like high impedance. If you put a buffer after a volume control, it makes the output impedance much lower. You can put buffers before and after a volume control if you want.

The thing here is to try to make a buffer that is very neutral. Given the simple task, it’s pretty easy to construct simple buffers with very low distortion and noise and very wide bandwidth, all without negative feedback."


lewm
13,511 posts
 
If you seem to have sufficient gain when running the Herron directly into your amplifier, then you might consider either a passive attenuator to insert between them or an active stage that itself adds no gain.  The passive attenuator requires a good impedance match between the Herron output section and the amplifier input.  Poor matching can detract from SQ.  The active type of stage that adds no gain is impervious to impedance matching, except that it has to be able to drive your amplifier.  An additional advantage of the latter may be the capacity to switch among different signal sources.  What you don't need is an active linestage that typically provides way more additional gain than what is needed, and in so doing adds its own coloration.
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