First impression: Herron VTPH-2A phono preamp

For normal listening levels in your setup where is your vc positioned on your active pre and do you know it’s gain? Does it have a log pot? And what is the gain of your amp and efficiency of your speakers?

Hi George,

My speakers are Daedalus Ulysses, which are rated at a high 97.5 db/1 watt/1 meter, and have a 6 ohm nominal impedance. I don’t know what the gain is of my VAC Renaissance 70/70 MkIII amplifier, but it is certainly not low, especially for the zero feedback setting of its feedback select switch, which is the setting I use.

For my preamp I used a DEQX HDP-5, which as you may be aware is produced by some of your fellow countrymen Down Under, and provides numerous DSP-based functions including improving speaker time coherence and room correction. To make that possible analog inputs are converted to digital, but the unit is renowned for its transparency and I have high confidence that it does not manifest any audible bit-stripping at any of the volume control settings I use for either CD or LP playback. I say that based on my own tests with both the speakers and Stax electrostatic headphones, as well as on numerous testimonials to the transparency of DEQX units by experienced audiophiles that are stated in the long running thread here entitled "Is DEQX A Game Changer." It provides 50K input impedance, and at its factory default settings I use I believe its gain is small, just about 1.5 db from unbalanced analog input to unbalanced analog output.

The volume control characteristic is described as follows:

Each button press increments or decrements in 1dB steps from 0dB to above -24dB, then in 2dB steps above -36dB, then in 3dB steps above - 48dB, then in 6dB steps down to -120dB.

Much of my listening is to classical recordings having wide dynamic range, and for those I commonly have the volume control set in the area of approximately -20 to -26 db or so, when listening to LPs. Those who listen to dynamically compressed pop and rock recordings would presumably use lower settings in most cases.

Again, I am using the 64 db version of the VTPH-2 and a 0.5 mv cartridge.

Best regards,
-- Al

Thanks celander, I'm enjoying it immensely. I'm only two days into the VTPH-2A experience and 100% sold out on the product. I'm 64 and have to admit that some of the vinyl I've listened to the past few days has made me as giddy as a kid. At least 50 years of listening to vinyl and I've never heard anything this good.

I had a few brief e-mails with Keith Herron since I purchased the preamp. In complete honesty and at the risk of sounding hokey, I believe he's invested part of his soul into what he's doing and it shows. I wish his company a large measure of success and have no reservations so far giving the VTPH-2A a five star, A+ rating.

@professorsvsu. Glad you’re enjoying your Herron phono stage. I owned one about a decade ago and loved it. 

Al, like I said before some of my customers with MC and 48db phono stages are having no problem, around 2pm on the VC, but then they have "normal" gain poweramps and speakers that are efficient.
If you run one of say Nelson’s low gain F series amps or similar then yes I agree there could be gain issues, lets wait and see what Rob67 has to report he has a MC that is a $10kusd Lyra, and his amp and speakers are in the "normal" rage of things.

BTW: For normal listening levels in your setup where is your vc positioned on your active pre and do you know it’s gain? Does it have a log pot? And what is the gain of your amp and efficiency of your speakers?

Cheers George

He’s given you massive 64db or 69db of gain, use it, some poor saps only get 35db of gain with their phono stages and they have to listen to the preamps output gain stage’s noise.

Hi George,

I’m not sure you’re realizing that the 64 or 69 db of gain is just for use with low output cartridges, primarily low output moving coil cartridges. Moving magnet or high output moving coil or high output moving iron cartridges are connected to a different input of the phono stage, which provides either 43 or 48 db of gain depending on the version of the phono stage.

64 db of gain is not "massive," it is an amount that is appropriate for the majority of low output moving coil cartridges. While 35 or 43 or 48 db are reasonable figures for use with most high output cartridges. Using 64 db of gain with a moving magnet cartridge would most likely result in an overload condition.

Best regards,

-- Al

if he says that 20K is a bare minimum

He’s quoting, like me saying 47k and 100k is even better is the figure for the Lightspeed to see, when in fact 25kohm is the min correct figure as measured and listened too by our 50 strong audio group, as that gives a 1:10 ratio as the max output impedance of a 10k volume control is 2.5k, were just taking in any unforeseen circumstances like weird cables etc.

We’ll see when Rob67 reports on what he heard, as for now as I said before lesser phono stages are sounding great into this kind of load.

Al do your ears a favour, ditch the dinosaur if you have the gain, and "not" listen to the noise floor of your preamps output gain stage, you’ll be amazed just how black the background of vinyl can sound if you utilise all the phono stage’s gain instead.
He’s given you massive 64db or 69db of gain, use it, some poor saps only get 35db of gain with their phono stages and they have to listen to the preamps output gain stage’s noise.

Cheers George

As for the 2.5v output figure into 20kohm at 0.03% distortion this is far less than what a cartridge has as a distortion, they are closer to 1% so to me that doesn’t mean much.

Hi George,

To be sure it’s clear, the point I was making had absolutely nothing to do with the distortion percentage. I was making the point that the 2.45 volt figure has no relation to how much voltage the phono stage puts out in normal use. It just relates to how much voltage it is **capable** of putting out, without exceeding the distortion spec.

And the 64 db version of the phono stage, which is what most people choose and which is what Keith recommends as being the best version to use with LOMC cartridges that do not have unusually low outputs, will produce an output far less than 2.45 volts under most circumstances. In fact well under 1 volt under most circumstances. Which in turn will be too little to drive many and probably most power amps to full power, even with the volume control at max, unless the preamp provides additional gain.

As I said I have customers with tube phono stages that have lower gain around 48db and 1kohm output impedance they don’t have any issue with not enough volume. I make it a point of asking where the volume control is for normal/loud listening, and they say around 2pm which gives them plenty of range up or down.

Surely that is with moving magnet or other high output cartridges, not with LOMCs!

Speaking more generally, given the credibility Keith has earned over the years as a result of his universally praised design work and sincere dedication to customer support, if he says that 20K is a bare minimum and 40K or more is preferable, that’s good enough for me.

Best regards,
-- Al

You’ve got the option of 69db of gain Al also have a look at the on line manual/specs.
Also with average gain of amps at around 27db and speakers that are average around 88db you certainly will have enough volume range

Maybe not with low gain amps as the NP Aleph’s and such, and low efficiency speakers such around 82db.

As for the 2.5v output figure into 20kohm at 0.03% distortion this is far less than what a cartridge has as a distortion, they are closer to 1% so to me that doesn’t mean much.

Well see what rob67 has to report re gain, as his Gryphon Antillion amp is around average at 1v sens and his Wilson Sasha speakers are around average at 90db

As I said I have customers with tube phono stages that have lower gain around 48db and 1kohm output impedance they don’t have any issue with not enough volume. I make it a point of asking where the volume control is for normal/loud listening, and they say around 2pm which gives them plenty of range up or down.
Many of my vinyl junkie customers are here on these forums, hopefully they will respond as I can’t remember who has what, as there are over 900 out there.


Cheers George

Wow! So bass rolloff would not be an issue that would result from driving low impedances such as 10K, with Keith’s design. But I would still take to heart his comments recommending against anything less than 20K. And his suggestions that for other reasons 40K or more is preferable with the 64 db configuration (400 ohms nominal output impedance), and 50K or more is preferable with the 69 db configuration (500 ohms nominal output impedance).

Regarding the 2.45 volt figure, while he has conservatively chosen that number for use in specifying distortion, keep in mind that a gain of 64 db will raise the output of a cartridge rated at 0.5 mv under the standard test conditions (that being the rating of the AT-ART9 which I and the OP and some others here use in conjunction with what I presume in all or nearly all cases is the 64 db version of the VTPH2 or 2A) to only 0.792 volts under the standard test conditions. Not nearly enough to drive many power amps to full power, even with the volume control of a passive preamp at max. Although very high volume transients on some recordings can exceed the standard test conditions severalfold, as I understand it.

In any event, thanks for obtaining the good info about the cap.

Best regards,
-- Al

Keith just emailed me, here’s what he said.

"Hi George,

Thanks for the note. The output capacitors of the VTPH-2 and VTPH-2A are approximately 7 uF (polypropylene) and the low frequency response is RIAA flat down to 10 Hz (within 0.1dB) into a 10k Ohm output load."

As you can see no problems with bass rolloff as the cap is 7uf and he’s done the measurements flat to 10hz, into the same load as a 10kohm passive represents!
My calculations with 7uf into 10kohm load are -3db at 2hz, perfect!

All looks fine to me for it to be used with a passive preamp, as the gain is very high for this phono stage, so you may as well utilise it all, instead of knocking it back because of the gain in an active preamp, this way you’ll get a definite lower background noise level.

Also Keith said the Distortion: Less than 0.03% at 2.45 volts RMS output at 1kHz at 20k Ohm, this also "to me" bodes well for passive preamp use. If you’ve got’em smoke em! to see how it sounds. We’ll see after this weekend what rob67 thinks of it with the Lightspeed as it mimics a 10kohm passive volume control.

I’ve got other customers of mine with tube phono’s that aren’t spec’d as good as this for passive use, they say it’s the best they’ve heard their vinyl sound, once they got rid of the active preamp.


Cheers George

that the manual recommends 50K or more as being optimal

Yes as I said before that could very well be because of the output cap size, as you know 400ohm is fine to drive a 10kohm load. 1:20 ratio is no problem even 1:10 also
We’ll find out that cap size if Keith emails me the info.

Cheers George

Hi George,

No, I don't know what the value of the coupling cap is, as I've never had occasion to open my unit.  One reason being that I've never felt tempted to do any tube-rolling with it, and in the process perhaps messing up the voicing Keith has achieved.

But in addition to what I mentioned earlier, that the manual recommends 50K or more as being optimal as well as Keith's statement that he would not recommend less than 20K, a few months ago he explicitly recommended to another member that the VTPH-2A not be used in conjunction with a 10K load, stating as follows (quoted by member Uberwaltz in a post dated 4-2-2018 in this thread):

Hi Kevin,

Thanks for the note. I like to see, as a general rule in high end audio, an impedance ratio of at least 1 to 100 (output impedance to input impedance) when using tubes or solid state as loading the circuits down generally reduces the quality of the sound. I have seen similar impedance ratio recommendations from Audio Research and other high end audio companies.

Solid state circuits generally have much lower output impedances than tube circuits. 10k Ohm input impedances are a standard typically used in professional audio, but this does not work as well for tube based high end audio equipment.

The two 12AX7, three 12AT7 version of our VTPH-2A has an output impedance of 400 Ohms which performs best into a 40k Ohm or higher line stage input. Some people are using them with line stage inputs that are a little less than that with reasonable results, especially if their cartridge has a lower output voltage. Your integrated with a 10k or 5k single ended input would likely restrict dynamics substantially, even with a very low output phono cartridge. I can't recommend that combination. Audio is supposed to be fun.

Another thing to watch for is that some line stages (particularly digital ones) have a very low input voltage limitation which can cause overload (clipping) with some analog sources. That can sound nasty.

For the reasons above I design our line stages with a 100k Ohm input impedance and a wide input voltage margin in order to get the best sound quality from tube based sources such as phono stages, tape machines, tuners, and DACs with tube output stages. I wish everyone would do that.

I hope this short explanation helps.

Best Regards,

Keith

Best regards,
-- Al 

almarg

I can see where your coming from Al, the 400ohm is fine, as you say if the output coupling cap is too small there would be some rolling off the bass too early with a 10kohm passive.
 
I just did some calculations and if that coupling cap is 1uf or more all is fine. Do you know how big it is maybe you have one? I have sent an email and asked Keith I will post it up when he reply's. 

And if it is less than 1uf there's no trouble or much cost making it bigger, and at the same time a better quality one.

And the gain can be either: From Herron
Gain MC Mode
(2 X 12AX7, 3 X 12AT7) 64 dB
(4 X 12AX7, 1 X 12AT7) 69 dB

Cheers George 

@dweller -- a while back there was a thread on the Chinook, and I distinctly remember more than one responder saying the Allnic H1201 and Herron VTPH (sorry, can't remember version) were significantly preferred in comparison.  Not surprisingly, there was praise for the Steelhead although obviously at a higher price point.  Just dusting off some synapses here and sorry for the sidetrack, but hope it helps. 

salectric,
I owned a Vincent and two Graham Slee phono preamps as well. They were disappointments, especially for the money. Until I purchased the VTPH-2A, the best bang for the buck phono preamp that I've owned was the Neo 310LP.

Professorsvsu, congratulations and continue to enjoy! I know you will, being one of several other members here using the VTPH2 or 2A/ART-9 combo.

Regarding passive preamps, the Herron phono stage is not suitable for driving a low impedance passive preamp. One reason being that its nominally 400 ohm output impedance undoubtedly rises to much higher values at deep bass frequencies, due to the use of a coupling capacitor at its output. (Also, btw, the configuration providing a 400 ohm output impedance provides 64 db of gain, not 69 db as was stated above. And I assume you have the 64 db version, which is what I and most VTPH owners have purchased).

From the manuals for the VTPH-2 and 2A:

We recommend that the VTPH-2A be used with a line stage having an input impedance of 50,000 ohms or higher for optimum performance.

And a direct quote of a response Keith Herron provided just yesterday to a member who asked him if the VTPH-2A could be used with a 20K load impedance (see this thread):

"We have VTPH-2A customers that are using preamplifiers with 20k Ohms RCA single ended input impedances that are pleased with the sound.
I don’t recommend going any lower than that. The 2 X 12AX7, 3 X 12AT7 version of the VTPH-2A has an output impedance of 400 Ohms so it will drive the Ayre preamplifier much better."

Also, I suspect that the degree to which those driving 20K with the VTPH-2A are "pleased with the sound" depends on how much deep bass extension their speakers provide, since one of the major consequences of this kind of impedance issue is deep bass rolloff.

Best regards,
-- Al

Prof--glad you like! One of those rare products in high end that exceeds the hype and yet somehow flies below most people's radar. What you get: SQ approaching the limits of what is possible yet a relative bargain compared with most ultra-high-end stages AND what is arguably finest customer support extent. Have fun!

Prof, you mentioned the Parasound and Sim Audio phono stages.  What were the other three you tried previously?

Yeah I saw that with the 4B cube it has two switchable gain settings.

Here’s something you may like to know, "if" this gain changing is done where most are done, the same way I used to do my tube or solid state amps I built, via changing the nfb (negative feedback ratio).
Then you may like to know that a higher gain setting is a lower feedback ratio, which "can" give the 4b a slightly more tube sound with a little less damping factor and maybe more 2hd.

Cheers George

georgehifi,
Before I start rewiring my system, I'll probably set the gain as low as it will go on my preamp (Parasound JC 2 BP) and kick the gain up on my 4B Cubed. A fun adventure for tomorrow. As far as the Goldpoint is concerned, I haven't used it in about six years and really don't remember the impedance. I'm sure I have literature on it somewhere or it's tagged on the unit.
Just finished listening to some old Starship, Knee Deep In The Hoopla. I'll bet I listened to the song Sara six times. The VTPH-2A is something really special. I've gotta know what rob67 thinks of the unit in his system. I wouldn't be surprised if it puts a grin on his face from ear to ear.

Yes do try it, because with all that gain the Herron has, you may as well use it all and not have more noise from active pre’s that you’d have to turn right down to throw away the gain of the Herron.
Do you know what the impedance of your Goldpoint is?? ( 5K, 10K, 25K, 50K, 100K, and 250K.) hopefully it’s the 10k one as this will suit nearly all situations, as this is important to get a good impedance with your amps input impedance if you know that too? I believe you have the Bryston 4B cube which is 33kohm rca that’s fine if the Goldpoint is the 10k one.

Cheers George

georgehifi,
I would be excited to read about how the Herron performs in a truly high end system. My system is almost a starter kit in comparison.
I'm glad that you brought up the Lightspeed. I have a Goldpoint floating around that I haven't used in years and I may experiment with that as well when I have free time.

professorsvsu
First impression: Herron VTPH-2A phono preamp

rob67 has one of these Herron’s phono stages, and because it has nice low 400ohm output impedance for a tube and high (69db) of gain, he probably doesn’t need any more gain from an active preamp, so he’ll be trying it out with his new Lightspeed Attenuator (should be far lower noise this way) he should have it this weekend which will be driving into his Gryphon Antilleon Signature poweramp driving his Wilson Sasha’s, I’ll ask him to comment on the sound here for you once he’s had a good listen..

Cheers George

Dear professor, congratulations! I am also a very happy owner of a VTPH2A. It is truly a great product, backed by the best customer service that you are ever likely to encounter. Have fun! 

dweller,
I have not heard the Chinook, although it's my understanding that it is quite good as well. My last two preamps were both solid state, the Parasound JC 3+ and Simaudio Moon Neo 310LP. The JC 3+ was new and returned after a few week audition. It was okay, but I couldn't live with it's noise. I went through the whole dog and pony act of isolation, changing cables, grounding, etc. to no avail. Parasound believed the unit had too much gain for my system and was willing to trim back the gain if I wanted to send it back to them. Great offer, but it was disturbing to think a new item would need factory alteration right out of the box. The 310LP is a gem in it's own right, just not complete enough.
I digress. My advice would be to audition, if possible, whatever it is you are strongly considering. I was afraid with the VTPH-2A that I wouldn't be objective, that the power of suggestion in reviews would influence my thinking. All I can do is concur with what I've read, it is the most musically dynamic component in my system. The AT-ART9 cartridge I use sings with accuracy. The beryllium tweeters in my Focal speakers offer clarity to highs like never before. I can finally understand the definition of tight bass and vocals that are live. If you listen to the Chinook and can have that kind of experience with the music, you've hit the jackpot. If not, I'm sure that you'll find it with the Herron. 

Professor: Have you ever owned/heard a manley chinook? I'm trying to sell my McIntosh C22 reissue, which I use for phono duties, as I rarely listen to vinyl and can't justify that much capital sitting idle. I'm planning to replace with a chinook or the Herron. Can you compare the two?

Glad to hear. Its supposed to be one of the best phono stages on the market and I've yet to hear someone who has complained about its performance. I've had my eye on his linestage and its just a matter of time before I yield...Congratulations.