I would like just a little more gain for ultra low output cartridges and I believe from what I have read that a balance design should have lower noise levels. Cartridges are balanced to begin with.The reduced noise can be significant. For a given gain stage, if executed in the balanced domain you get a maximum of 6dB less noise. Now if you have two gain stages or more this adds up.
Phono Preamp Tube Rush
Is there such a thing as a tube phono stage that doesn't have tube rush? Is it just an inherent weakness of that type of pre or is it some combination of cartridge gain and preamp gain? I went from a silent solid state ASR Basis Exclusive to a Herron VTPH-2A (new home with space limitations) and now I'm using a Hagerman Trumpet with my Decca London Super Gold. Both the Herron and Hagerman have tube rush. The Hagerman beats the Herron in my setup and it really sounds incredible but in quiet passages and between songs, there's that hiss at high-medium and high volume. It's just there. No combination of new tubes, new cables, etc changes this fact. Same with the Herron. Anyone having a different experience with a tube phono preamp?
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noromance"It's also possible that some phono amps "throttle down" gain with no signal present" That is ridiculous there is no such phono preamplifier in existence that is intended for Music Reproduction Systems. |
Yes Ralph you are correct usually j fets I think and I do believe it is to reduce noise. My next phono amp Is going to be balanced. Can't wait to try that. I would like just a little more gain for ultra low output cartridges and I believe from what I have read that a balance design should have lower noise levels. Cartridges are balanced to begin with. |
There's a fair bit of noise with my Herron. Its actually a bit noisier than the ARC PH3SE that I had for many years before that. Although in fairness I should say most of the noise I'm hearing is not due to the Herron per se, but the particular interaction with my arm cables and cartridge. In other words it could be reduced, and would be, if it was that big a deal to me. Which its just not. Nor does it seem to be that big a deal to any of the many people who have been over to listen. Maybe link this thread to the other one as inordinate fuss over a little hiss definitely sounds like "What is wrong with audiophiles?" to me. |
Again I agree with @daveyf , you can hear tube rush noise on any tube phono stage with just a slight bit of effort (or no effort, depending on the unit). It’s there. Yes the Herron VTPH-2A is very very low noise, one of the lowest I’ve heard - still there. And low noise tube selection is a must, but there’s no magical premium-platinum-plus selection that’s going to make it go away completely. It’s an issue of gain - a LOT of it is needed to amplify cartridge signals. That said, for my ears, when you get to the low noise level of a VTPH-2A or my VAC phono, it’s low enough to not bother about, since groove noise will take over from there. On the other hand, hum and buzz from grounding issues are positively insanity-inducing until resolved. I've also had the experience that some NOS tubes can make for a substantial increase of enjoyment over new production, despite the increased difficultly of finding super low-noise examples. |
@three_easy_payments - I thought my post was very clear in that the phono stages mentioned may sound great but if the unit has noise then IMO something is not correct. Why would I buy anything that had noise? Like I said, these products may sound great but the designer did not take the time to design the unit to eliminate the noise so IMO that is a compromise in the design, maybe to make something at a price point possibly. I don't use 6922/6DJ8 in my phono stage either. The 12AX7 tubes work better in that application. Happy Listening. |
dhcod, It would take a severely defective tube to cause a 25% decrease in sound quality. I have not used a 12AX7 unit since 1965 and a Dyna PAS 3X but with 6922's the only significant difference between tubes is noise which is much easier to quantify than sound quality. Whatever differences there are in sound quality are marginal at best but having all kinds of crap going on in the background of quiet passages is annoying. I suppose if you only listen to Metal it does not make a difference and besides the tube with those gold pins must sound better. |
@ three_easy_payments I agree. The VTPH-2A is a very highly regarded and designed unit. Even way above its price point. And very musical. There is unanimity on that. As for tubes, I eventually found a set of 12AX7 EH tubes that tested and sounded better than the ones I had. It did make a difference. But then I found some NOS Ei tubes and they were even quieter. I'm using the 12AX7 Ei in V1 and V1 and 12AT7 Ei in V5. |
FYI, When I had my VTPH-2a I noticed no difference in noise between the lowest noise new stock tubes and NOS telefunen 12ax7s and Mazda 12 AT7s. I had the version with the 2 12ax7s and 3 12AT7s. I loved this unit and compared it to a few others that were more expensive and it always won out. When I went with the Decca cartridge though, the Trumpet was doing all the same stuff but with some noticeably extra depth in the sound stage so I made a change. Keith Herron is the best. I still have his line stage and amps. |
@bigkidz I have to disagree that the VTPH-2A is a poorly designed unit as it’s incredibly musical, especially at it’s price point. I really love what it has done for my vinyl experience. With that said I do wonder why Keith didn’t use the 6922/6DJ8 in his phonostage which is what he uses in his linestage. It seems noise would be much less of an issue because the EH 6922 is one of the quietest tubes there is for this purpose with ample gain. |
I have never heard an ARC phonoamp with "tube rush." They do have noise way down which is not a factor up to 110 dB in my system. I do use super low noise 6922's from Roger Modjeski's tubeaudiostore.com. He measures every single tube and puts them into three categories, standard, low noise and super low noise. The super low noise tubes are said to be one in 100 tubes tested. I have purchased 6 tubes and they are all obviously quieter than the ones ARC supplies. From my experience NOS tubes are a rip off. I had NOS Telefunken 6922s and they were no where close to Roger's tubes as far as noise is concerned. With Roger you know exactly what you are getting which is very reassuring. If your phono amp is noisy with super low noise tubes then it is either defective or a bad design. |
I also have the VTPH-2A. Great phono stage. I am using a Hashimoto HM7 SUT with it. At one time, I did have a little tube rush that could be heard from my listening position if I maxed out the gain on my preamp with nothing playing. So, I tried different things - changed/added grounding for the TT; changed the tubes in V1 and V2, and also V5; made the ground wires/connections a bit tighter; moved my SUT around relative to the TT and phono stage; used different shielded interconnects; created some flexible outside metal/copper shielding for the shielded interconnects from TT to SUT and from SUT to VTPH-2A, with the shielding then grounded to the ground posts. Each had a small but additive effect on S/N, eventually reducing noise by about -12dB to what the VTPH-2A is specified at (e.g., around -90dB). You should try some of the little incremental improvements that are out there because they can add up nicely and reduce noise. Noise is rarely just because of 1 piece of equipment or 1 issue. Now, with max gain on my preamp, I can only hear a faint bit of tube rush if I place me ear right against the speakers. That’s what I would expect at -90dB. Otherwise, from my listening position, it is dead quiet. YMMV. |
I can certainly identify with this topic and the advice so far has been spot on consistent with my experience. I too have a Herron VTPH-2A and noticed tube rush only a foot or so from the speaker when volume is up quite loud and BEFORE needle touches the vinyl. I have found a bit of success (in my quest to lower the phono noise floor) by moving from a 0.3mV cart to a 0.5mV and by dialing gain and loading through a Zesto SUT. I've had discussions with Roger Modjeski about possible noise reduction using his SNL tubes (at ~$100/ea) in the 1st gain stage of the Herron. He thought it might lower the noise floor a few dB but he said it's hard to say. Haven't pulled the trigger on new tubes yet. |
I have a Musical Surroundings Nova Phonemena (solid state with a DC power supply) and a Manley Chinook (tubes). If I turn up my preamp to the 12 o'clock position with nothing playing, I hear no added noise with the Nova. There is an audible increase in the noise level with the Chinook, but it's not overwhelming. I don't notice the additional noise from the Chinook when I'm playing records and that 12 o'clock position on the volume dial is about as loud as I listen. Which pre do I like better? The Chinook. So yes, some noise is the price you pay for tubes. I have low noise tubes that I purchased from Brent Jessee and I think they helped, and I'll take a little bit of noise to get that tube magic. |
As mentioned above, tube rush is a fact of life with tube phono stages...to a greater or lesser extent. Even with matched NOS tubes, the amount of rush will depend on how much gain is applied to the tube. When i hear folks say they have no or very little tube rush, that tells me that they are not listening to the speakers that close....or at very high levels. Push up the gain...and there comes the rush. I have fought this battle for years, as my CAT preamp has had a number of different NOS tubes rolled into it..and there is always some tube rush...IF i listen very closely to the speakers. Not bothersome to me, and I do NOT hear it once the music is playing, but it has always made me question how much is actually lost in the presentation of the music vs. a ss device that is perfectly quiet ( if there is such a device)...vs how much is lost due to the beauty of tube phono stage reproduction vs. ss phono stage reproduction. I still way prefer tubes. |
@dhcod- You mentioned having tried new tubes. Were they graded for low noise? You probably already know, but, just in case- some tube vendors grade their tubes. Some don’t. ie(check what’s said, regarding, "Platinum Grade" and, "Kevin’s Stash"): https://www.upscaleaudio.com/pages/grading-matching |
Those are 2 popular units.,one of which i've tried.-Herron. No noticeable tube rush at "reasonable" volume, from the listening position. If you're expecting SS, absolute quiet during blast sessions,in between cuts-good luck on that. Even the finest at unreasonable volume, have some leve of hiss. Real amplified music is noisy. A Fender or Marshall at idle won't win awards for quiet. |
I use a Herron VTPH-2 (not 2A) in conjunction with an AT-ART9 LOMC cartridge rated at 0.5 mv, with the Herron's stock tubes and no loading plugs. If I turn the volume control in my system to a setting slightly higher than I would ever use (which is quite loud; some classical symphonic recordings I listen to can produce 105 db peaks at my 12 foot listening distance) the hiss produced by the phono stage is only audible within about 1 foot of the speakers. In saying that, though, I should point out that I believe the Decca London Super Gold cartridge mentioned by the OP is a high output cartridge, and while the moving magnet input stage of the Herron is indeed tube-based its LOMC input stage is FET-based (i.e., solid state). @lewm I believe what hagtech is referring to is Johnson noise, that would be produced to some (not necessarily audible) degree by any resistance. Regards, -- Al |
hagtech, In explaining that SUTs can be a source of noise, you wrote, "If they use too thin of wire the resistance gets too high and becomes
the main source of input noise." What??? Where does that idea come from? To begin with, the primary of a SUT is seeing the miniscule output voltage of typically a LOMC cartridge, like 0.5mV of AC, or less. |
I use a number of Deccas inc the SG and cannot recall this issue with my Croft 25R with Shuguang Black 12AX7LS. But then again, between vinyl roar, and tape hiss on older recordings, you’re making me second guess what I feel is a near silent amp. In my book, if there’s no trace of 60 or 120Hz anything, I’m golden! |
Between songs you hear LP groove noise. Lift the tonearm and I bet it gets much quieter. Then you will hear self-noise from input resistance and tubes. An good SUT can wonders, as they are mostly noiseless. But not always. If they use too thin of wire the resistance gets too high and becomes the main source of input noise. The low-end Cinemag was like this (maybe they have since updated). Mostly what you hear is noise from resistance, not tubes. |
It’s unfortunately a fact of life for us lovers of vacuum tube phono stages. Worse if you listen loud, like I do, of course. I’ve had the Hagerman and currently own a Herron. Both are about as quiet as low-rush noise as you’re going to get, especially the Herron. The Hagerman is a really nice sounding stage with romantic beautiful sound; I see why you love it. Sometimes I miss it and wish I’d kept it, but I moved on to a VAC that is better, though for much (!!) more money. If you like the Hargeman you’d probably love VAC phono stages, even the ones built into their integrateds and preamps. The ONE factor you can play with to combat rush noise is to get a cartridge with a higher output level - that allows you to lower the preamp volume, and audible tube rush will reduce proportionally. The other thing to note is that is you’re loading your cartridge very heavily, you will lose some signal and that will allow tube rush from your phono stage to creep back up in relative level. If you're using a low output MC cartridge, using an outboard SUT with a higher gain (and phono stage in MM mode) will also allow you to combat tube rush noise. |