I doubt it! Get a good mc transformer (SUT) to maximize the signal-to-noise range of the Koetsu - and your other mc"s.
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First, as wlutke says, the output is at least 0.4mV, unless the cartridge is in the Platinum series, which I doubt because I don’t think Koetsu made a Platinum version of the Urushi types. (Vermilion is essentially a red Urushi.) Second, it’s not a good idea to mate a SUT into an MC phono section even if the input resistance is 47K ohms, because you are very likely to overload the stage. If input R is the more typical 100 ohms or any value much less than 47K, that’s a much worse situation. Don’t do it. |
You drove me to go to the website. You are correct. Koetsu lists the Vermilion as having an 0.2 millivolt output, much to my surprise. All the other Urushi variants are listed 0.4 millivolts. I can only conclude that something is different about the Vermilion. I don’t recall ever reading anything about it, but you probably do need to proceed on the assumption that the output is 0.2mV. In which case your present phono stage is marginal at best. But it is still not wise to insert an SUT before an MC phono stage. I suggest you give it a try with your present set up, and then decide whether in fact you need a higher gain MC phono stage. I think Koetsu measures output at a stylus velocity of 3.54 cm/sec, the old standard. The new standard for many years is 5 cm/sec, which would give a higher stated output. You might luck out if Koetsu is understating the output by current standards. Like I said, my Urushi behaves as if its output is greater than the claimed 0.4mV. |
The spec on Vermillion is 0.2, and at least with the Koetsu Stones I’ve got their specs seem to be reasonably accurate (relative to Shelter, Ortofon) so I wouldn’t expect to benefit from some bonus output. You should proceed on the assumption that the Vermillion has half the output of any other Urushi (it uses a different coil design). I would not be happy with 58 dB on a 0.2 Koetsu. Not one bit. I’ve run 0.3 Onyx and Jade Platinums on a 60 dB Sonic Frontiers Phono 1 and it sucked the life and dynamics out of them (that phono stage sounds wonderful with other 0.5 - 0.6mV cartridges including an alnico Onyx). Koetsu work very well with SUTs into an MM stage, but that PH7 phono is not at all flexible enough to use like that. With that stage you’re kind of stuck with cartridges in the 0.5mV to 1mV range. I say it’s absolutely time to get a new phono stage. Don’t invest so much into such a wonderful cartridge and then squander it! |
Koetsu work very well with SUTs into an MM stage, but that PH7 phono is not at all flexible enough to use like that. I say it’s absolutely to get a new phono stage. Don’t invest so much into such a wonderful cartridge and then squander it! I gotta agree here. The gain is 57.5dB for both moving-magnet and moving-coil cartridges and the output from either goes through the same inputs and circuitry so you can't avoid the first JFET gain stage before going through the next tube stage (4 x 6992's). The PH7 handles all carts the same. Even if you could bypass the FET-based initial gain stage I'm not sure I'd want to try to use a SUT through four 6922's using a 0.2mV cart - likely would be too noisy. It seems this cart is better suited to SS phono pre. Just my opinion. |
Well, I checked here https://upscaleaudio.com/products/koetsu-urushi-vermillion but their info is wrong. Bad luck. Please consider that your $6000 PH-7 is about 12 years old and performs very poorly against today’s offerings at half the price. |
The advice to use a higher gain phono stage may be well taken and I agree it is probably not advisable to add a SUT to the PH7, but not because of noise. If there is a JFET at the input of the PH7, it is likely forming the bottom half of a cascode topology, with a 6922 tube on top. The gain comes from the combination of the JFET with the tube. Such a gain stage is actually very quiet. Or if there is no cascode, if the input gain is all coming from the JFET, that too is low noise. jlutke notes that at least one Koetsu dealer lists the gain of the Vermillion at 0.4mV. I have to wonder therefore whether the gain listed at the Koetsu website, which was probably created by the US distributor, is possibly in error. Because never before have I read that the gain of any one Urushi model is any different from that of any other.. |
I just noticed my Sonic Frontiers Phono 1 is JFET and 6922 like the PH-7, and with very similar gain. I’m telling you it goes from dead boring with the 0.3mV Koetsus to wonderful with my 0.5mV - 0.6 Shelters, Ortofon, and alnico Koetsu. I also have Rogue Ares Magnum, Herron VTPH-2A, and VAC Renaissance that all go far better with the 0.3 mV Koetsus. The Rogue is good (make sure you get the blue label CineMags), the Herron is a bit better, and the VAC is a lot better but for a lot more money. I like the Bob’s Devices Sky SUTs for the money, and I think they improve on the Herron’s JFET stage. A Sky 30 or 40 would go great with the Vermillion. The Hashimotos are also really good. I don’t like Lundahls. The Koetsu SUT is superb but hard to find. |
I did not say, nor did I intend to say, that using a SUT is a bad idea. I only say that using a SUT with the PH7 would probably be a bad idea. Because it would likely overload the PH7 resulting in distortion, and because the PH7 at the very least would need to be modified to present a 47K ohm input load resistance, if it doesn't already come so equipped. Using a SUT with a high quality MM stage might be fine. Another factor that has been excluded from this discussion is the additional gain, if any, provided by the OP's linestage. Most linestages add 10db to 20db of additional gain, unless one is using a passive stage. So, mulveling, when you got your mediocre results with 0.3mV cartridges, what was your linestage gain? I ask, but I don't want to be in the position of insisting that 58db of phono gain is "OK' with an 0.2mV cartridge. I do agree that more gain is better in this case. |
@lewm At one time I was using that Sonic Frontiers with a Hera II linestage that had gobs of gain (over 20dB, much more gain than the 15dB specd for the Hera I), and it didn’t help pull the dynamics back. Plus very high gain tube amps (over 36dB) and 96 dB / Watt speakers - I wasn’t wanting for gain in the overall system. It could get really really loud, and had a lovely midrange and treble, it was just sad and lifeless with no bass impact. The Koetsu Platinums came to life with any of the other phono stages I listed. I also used the SF in a high end Stax headphone setup (009, T2) with SOTA Nova, and same conclusions with same set of cartridges. I agree with you, I wouldn’t ever try a SUT with either the Sonic Frontiers or the PH-7. Just the wrong configuration for that. |
So I guess the output of your phono stage was just not sufficient to drive the Hera linestage for it in turn to produce enough signal voltage to drive your amplifier. (The results are dependent upon the input sensitivities of each of the components in the chain, not merely their respective capacities to add gain, as I am sure you know but just for others to benefit.) Clearthink, I beg to differ a little with what you say; most active linestages do add gain, typically 10db to 20db. Unless one is using a passive attenuator, there will be some added gain from the linestage. I'm not saying this is a good thing, necessarily; it's just most common in my experience of looking at specs. A few phono stages that offer the option of being used as full function preamplifiers do use only a cathode follower in the linestage section, which adds no gain but permits the linestage functions, like introduction of a volume control and switching of CDPs, etc. My Manley Steelhead is like that. |
@andychris Even if it seems to work quite well now, I wonder would you say the same after hearing your low-output cartridges with a better matched higher-gain phono stage? They could sound good and still be held well back of their potential. Expensive cartridges are not cost effective unless configured to their full potential. If you're set on keeping the PH-7 for now, I'd strongly advise forgoing the 0.2mV Vermillion in favor of ANY of the other 0.4mV Urushi models (only the Vermillion is different). That will be a much better match for your phono stage. I'm not even saying the PH-7 is necessarily out of date or not great sounding, just that it seems optimized for a very specific output range of matching cartridges and the Vermillion isn't it. I've also had an Ortofon Jubilee (exact same specs as your Cadenza Black that replaced it in the Ortofon line) and it didn't sound as good as the higher output Cadenza Bronze (0.45 mV) on my Sonic Frontiers with similar config as your PH-7. |
I had the sonic Frontier Phono 1 with the same tubes E188CC that my PH7, you can't compare those 2 phono stage, the sonic frontier doesn't make the music that the PH7 is able to do. I also had an audio research phono ref2 and I keep my PH7. Of course the 68db of the ref2 is fine on paper but there was less music out of the ref2,,, and I don't know why... but it's not a question of number on paper and kind of tubes.... the probleme is to get those components at home for a few days and make some A-B tests,,, and don't think about he price they cost, because more expensive doesn't mean better |