the Herron is problematic to roll for better sound.
That's an odd way of putting it. The Herron comes with such high quality tubes it is hard to find better. Yes. Much better. Carry on.
Herron VTPH-2A vs Rogers PA-2 Phono Preamplifier
I suspect the Herron might respond less obviously to tube rolling because it uses an FET (transistor) in its MC gain stage. Thankfully, transistors are hard soldered in place. Otherwise folks would be transistor rolling. Is there some reason to believe the Rogers unit would be competitive with the highly regarded Herron? Why would you use tube rolling as a criterion by which to judge? Real improvements to be obtained by tube rolling, unless the replaced tube is worn out or defective, are very limited and subjective only. Usually the practice does not raise one piece above another if it was inferior to begin with. In my opinion. |
It's not that the Herron's tubes are so "high quality"; in fact they are among the cheapest you can buy on the market. Keith did make sure that the batch of these cheap tubes that he uses are quiet. The Herron is voiced for the EH tubes - by design. Keith designed the pre so that you can easily replace with other cheap EH tubes when the need arises - a smart design. However, if you don't like the "voice" you should look to another phono pre. Other phono preamps can produce different sonics when you roll the tubes - whether they are better is debatable and a matter of personal taste. |
I know nothing about the Rogers unit, so can't help you there. Frankly, the VTPH-2A sounds so good with the stock tubes I've never given any thought to opening the case to even bother to see what tubes are in it. And this is from a guy who has hundreds and hundreds of dollars of tubes that I've tried in my last preamp. By the way, I have also not looked inside the Herron VTSP-360 ESP that I replaced that tube preamp with either. It's also that good. |
lewm ... if you’re using an LOMC cartridge, you’re basically listening to an FET. If I understand the Herron phono correctly.Not really. It's not unusual for a tube phono section to use an FET at the MC input. ARC does this in its Ref Phono preamps and they sure don't sound like listening to an FET. |
Please describe what listening to an FET in the context of a tube circuit sounds like. ARC preamplifiers are certainly not known for warmth. FET/tube phono stages can be among the most neutral. I certainly don’t mention it as a criticism of the Herron. My Manley Steelhead is also a hybrid as are many other phono stages we like to think of as “tube” types. Typically you have at the input a cascode consisting of a FET on the bottom and a tube on top. That gives tremendous gain and very wide bandwidth. It also eliminates or drastically reduces input capacitance. My point was that in this topology much of the gain comes from the FET. Therefore shuffling tubes downstream would have less noticeable effect on SQ, compared to an all tube circuit. Alternatively the FET drives the grid of what would be the first gain tube in a conventional tube RIAA. The FET acts like an outboard head amp . |
A different topic. To SUT or not to SUT. I had just edited my previous post to include mention of the type of circuit that you describe for the Herron. My own SilvaWeld SWH 550 phono stage is configured the same way. The FET drives essentially an MM phono stage when you are using an MC cartridge. Less interesting but more adaptable to a MM/MC switchable phono layout than is the cascode topology. |
There is a Rogers unit for half the MSRP on USaudiomart. https://www.usaudiomart.com/details/649709740-rogers-pa-1a-phono-preamp/ Its overall construction and performance are at minimum equal or "better" than the Herron. Interesting looks with the red paint and meters. The Rogers also uses FET in the circuitry. Most everything on the market employs a similar topology. |
Nice write-up on tube rolling in the Herron. Tube Rolling the Herron VTPH-2A Phono Preamp | Steve Hoffman Music Forums I've not seen an amplifier that does not respond to rolling and this post sums up what to expect. |
In my experience, tube rolling with the Herron is possible but difficult. The biggest problem is that the supplied tubes are extremely low noise, and most other tubes can't meet that low noise standard. And I'm sure the VTPH-2A is voiced with those specific tubes. The one tube I've had success with, though it doesn't really change the character of the sound in any meaningful way, are hand selected new stock Mullard CV4004(12AX7) from Upscale (Kevin's stash) and Mullard ECC81(12AT7) also Kevin's stash. I tried some NOS Telefunken Diamond 12AX7's I had lying around, but they were much noisier than the aforementioned tubes. Though I think I'll just stick with the stock tubes when it comes time to replace them. |
+1 @three easy. I've had this conversation with Keith and never thought about rolling again. The tubes he chooses are carefully selected, just like the other critical parts in his designs. They may not have the kind of name recognition or "bling" factor others possess, but they WORK as intended in his designs and they continue WORKING for years and years without hiccups. So roll away with that in mind or maybe find something else to tweak and scratch that itch. |
Agreed. “Problematic” not the best choice of words as it might suggest a negative.the Herron is problematic to roll for better sound.That’s an odd way of putting it. The Herron comes with such high quality tubes it is hard to find better There is a Rogers unit for half the MSRP on USaudiomart.It is the PA-1A model while the latest is the PA-2 model. Couldn’t find the model differences online so I reached out to Roger via email- still awaiting reply The reason for this post is not necessarily to distinguish the best sonics between Herron and Rogers, rather, it’s to find out if I like a quality “tube” phono stage. VDH Grail SE is my current “current type” phono stage. Perhaps Rogers may be a better choice because it’s easier to tube roll? |
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find out if I like a quality “tube” phono stage." If that's the case, expand your quest outside of made in USA gear and look at the the other players. Allnic http://allnicaudio.com/product/h-5500/ Luxman https://www.musicdirect.com/phono-preamps/luxman-eq-500-phono-preamplifier Rarely discussed-Icon Audio https://www.musicdirect.com/phono-preamps/icon-audio-ps3-mk2-mmmc-phono-preamp For maximum tubes, this is what you want https://theaudiophileman.com/nvo-spa/ current listing https://www.audioasylumtrader.com/ca/listing/Phono-Preamp/NVO/NVO-SPA-ll-2-SE/Tube-Phono-Stage/21045... Audio thread hot 10 years ago. |
I have the Herron and cannot see anything the least bit hard about tube rolling. Unplug it, take the top off, pull tubes out, put tubes in. If that is too hard then leave the cover off. Once you get in there by the way there’s about a bazillion things you can do for at least as much improvement as tube rolling. Like someone said good thing transistors are soldered or we’d be dealing with questions about transistor rolling. Diodes? Anyone?? |
I think my thinking is in line with MC's here. There is no piece of audio gear that could not be picked apart by a hobbyist competent to read a schematic and understand the circuit. Even those FETs could be substituted by a knowledgable engineer who can solder. The diodes might be upgraded if they are not already Schottky types. You could "upgrade" the resistors using nude Vishays, at $12 a pop. Capacitors are always a target of the cognoscenti. And yadayada. I've been down all of those roads myself, but I finally concluded that sometimes it's better to leave well enough alone. |
" find out if I like a quality “tube” phono stage." "If that's the case, expand your quest outside of made in USA gear and look at the the other players." We vinyl lovers are truly blessed, as there is certainly no shortage of fantastic phono amps to choose from today :) If you are interested in a pure, all tube phono stage... I've really been enjoying my Wavestream Kinetics Deluxe Reference Level 5.1 phono amp. This is the most recent and up to date version. It is an all tube design currently using (2 x 12AX7, 4 x 6DJ8); with extremely low noise (I believe with the external power supply that the current Level 5.1 Reference now comes with) noise is below 1uV (one-millionth of a volt ); providing 3 front panel selectable inputs = two MC at 62 dB of gain (without the use of SUT’s or FETS) with a useful cartridge range of 0.2mV to 1.2mV and one MM output customizable to your desire (you are able to choose your MM gain or you can have 3 MC ); having both balanced and RCA inputs and outputs; adjustable loading available on the back panel via custom loading plugs; and an essentially flat RIAA EQ curve within one tenth of a dB (.1dB) from 3 Hz to 40 Khz. *** The above specs are from the best of my recollection - if you have interest, please consult with Scott Frankland to confirm. He is wonderful to communicate with. *** It is very dynamic, both in the micro and macro sense, throughout the entire frequency range. It produces rich harmonics that are exhilarating when listening to violin/cello/acoustic bass, both reed and brass instruments, vocals, etc... all without sounding syrupy. It is extremely quite, plenty of gain and very pure sounding... due to not having to use any FET or Solid State devices, no need to use Step Up Transformers and their extra set of interconnects and connections or having to fight with hum issues. It is a very well thought out design, by an extremely talented designer and a true gentleman who is absolutely fantastic to deal with, Mr Scott Frankland. I feel very blessed to be able to have this piece in my system. At $9K new, I feel it is an absolute steel. Once in a very great while, you might see one come up for sale on the used market, but not very often. I consider this to be a true testament to the greatness of this phono amp as people who own it, hang on to it. It is not a "flavor of the month" type piece, but rather something that you cherish and would like to pass on to your children. In any case, just another excellent option to be considered :) Best wishes, Don |
That's missing the message about the Herron. What's hard is IMPROVING the sound of the Herron via tube rolling. I know. When I say he uses quality tubes you attack me saying they are cheap and common. But then when I say they can be improved you attack me saying they are so good improvement is impossible. At least you are consistent. Unfortunately only in attacking me no matter what I say. There's no missing that message, that's for sure. |
I have no experience with the Rogers unit. The Herron is hard to beat in its price range. I bought a Cary Audio VT-500 about a year ago and found it to be a little more dynamic and detailed than the VTPH-2A. The VTPH-2A has moved to a second system. I'm surprised the VT-500 hasn't received more buzz. It's currently on sale at the Cary direct web site for $3600. |