You might look into a bob's devices SUT. He makes very good performing units for the money. I used one on his SUT's for a 103R and it did a great job.
http://www.bobsdevices.com/
Chuck |
SUT-less high gain phonostage to replace low-gain phonostage will do the best work.
Tube box is popular so selling it isn't hard to get some 'upgrade downpayment' that will end up more cost-efficient than SUT. |
Good advice. Although there are not many models available in Argentina right now -and we cannot buy electronics from abroad, believe it or not. There's a Clearaudio dealer... maybe some mid-range Clearaudio pre + Denon au-320? That may work better than keeping my Project, perhaps... |
The Micro-seiki "head amp" IS an active gain stage, which if it does not result in noise, can often provide better results than an SUT which can result in ringing and will "magnify" any cable or loading mismatches. |
Oh. I have no experience whatsoever with any of these pre-pre gadgets, but from what I read, the SUT au-320 should match almost exactly the cartridge impedance. That's why I assumed it was a safer choice. I didn't know about other risks (ringing or cable mismatches)... |
agree with Swampwalker, but still believe that having one-piece high gain stage is more beneficial than two-pieces and even more financially efficient in some cases. I also don't believe that going super-low out cartridge with all SUTs and highest-gain possible stages would stand next to cartridge with sufficient output for single-piece phonostage or phono-board. Denon cartridge + Denon SUT looks to me that there's better cartridge for the money with sufficient output. |
Fedocable- Marakanetz MAY be correct but if there are import limitations it might not be possible to find a sufficiently high gain full function pre-amp or phono stage. Using the KAB gain calculator, a cart w 0.2 mV output requires about 64 dB of gain. The Pro-ject Tube Box II provides 60 dB of gain. Pretty much any active pre-amp will provide the additional 5-10 dB gain from the line stage, so inadequate gain may not be the problem. I'm assuming you have switched the selector on the back of the Tube Box to MC and are running the output of the Tube Box into a line level input of a pre-amp. |
I would have no problem with the Denon SUT into your Project...especially if you like the sound of the Project. To change for something else would mean change of bigger magnitude and quite frankly it may not work for you..... |
Oh, I didn't know about the KAB gain calculator, thanks for the info! So my impressions were correct: for a 0.18mV -that could even be less, who knows- you should require no less than 70dB. That would put the Clearaudio Nano preamp -a third option I was considering- in a dangerous zone, since it gives 67dB of gain. It seems I'll be safer with the Denon SUT (or the Micro Seiki!) and my Tube Box. Later on I can always reach for a better preamp.
Btw, of course: the Tube Box is switched to "MC" and it's connected to a line level input. And the sound is horribly weak.
So, having ruled out the Clearaudio, I'm back at square one: Denon SUT or Micro Seiki head-amp? Why do you think that the head-amp could give better results, Swampwalker? The problem is that there are absolutely NO opinions about this unit on the internet -only some specs... The seller tells me it's a "single ended class A" -I don't really know what that means, in case it's good. |
Correction: according to KAB, the needed gain for my cart is 65dB. Still, I think that investing in a 67dB preamp like the Nano would be pushing the envelope... |
Fedocable- Your welcome. I suggested the head-amp because in a highly resolving system, I have preferred a high gain active phono stage vs. a xformer. I have very little technical expertise in this area, but I am told that one of the reasons is that xformers can "ring". Also, load matching is critical; I have heard differences in sound between only a couple of ohms in a xformer that has the the ability to swap in different values. I don't think (but really don't know) if that is an issue w the head-amp. Finally, the "step up" effect of the xformer also "steps up" any artifacts from the cable that is upstream of it. The 30 dB gain of the Micro seki is more than adequate and should allow you to run it into the MM side of the project (30 + 40 = 70 dB), which would tend to lower tube noise (if any). It's battery operated so no AC noise issues and has outstanding S/N spec (-120 dB). All that being said, a properly matched xformer can give very good results. |
Yes: the head-amp seems riskier, but could also give better results. But keep in mind that -on the papers- Denon's cart and SUT are made for each other: the SUT can be set to 40ohms, which is supposed to be the internal impedance of the cart. And the SUT would go too into the MM input of the preamp, lowering tube noise. But despite all that the Micro keeps attracting me -the attraction of unknown, I guess. |
Swampwalker, you are absolutely right: the Denon SUT has only 20dB of gain. That would make only 60dB when connected to the Project in MM mode (40dB). Not enough! Suddenly the SUT is no longer the safer choice, apparently! What do you think? |
Well, you know that 60 dB of gain is not enough, so you'd have to use the MC input which would give you 80 dB, which might very well be too much, depending on how much gain your line stage and amp supplies, room size, etc. If that were the case, you'd end up operating at the extreme low end of the line stage's attenuator, which generally is not a good thing in terms of channel matching. It also would create a big problem if your line stage uses a stepped attenuator and or has a logarithmic attenuation curve. |
Oh, to be honest I have absolutely no idea about those technical details... My amp is a Puccini Settanta (70W), that's all I can tell you. And my set is in a fairly small room. But as far as I understand, I like the idea of using the MM input: it would mean less tube noise -and there is some... |
Looking at some comments on-line about the amp you are using, there are some suggestions that the gain steps are a bit large at the lower end of the scale, so I think that 80 DB of phono gain would be too much; leaving you wanting more fine control of volume. So that would argue for the Micro Seki into the MM input. |
Thanks, that's extremely helpful! Btw, the Puccini Settanta is already a nightmare when it comes to "volume control": you need to have surgery precision with that knob.
But anyway I'm growing the idea of replacing it with a Primaluna Prologue Premium, for the sake of tubes. |
the Puccini Settanta is already a nightmare when it comes to "volume control": you need to have surgery precision with that knob. That's what I was learning from the web reviews I read. Excess overall gain coupled with a finicky attenuator is a recipe for total frustration. |
