Rethinking Phono Preamp Gain Settings

Discussion in 'Audio Hardware' started by avanti1960, Jul 8, 2017.

  1. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Ok, so the internal impedance here is 30 Ohm. Copla might work, as it goes up to 300 Ohm loading, but:

    A) The cart may like more than 300 Ohm, you never know until you try;

    B) Because of the transimpedance dial, at 300 Ohm impedance it provides only 9 dB of additional gain. Not sure how much gain your phono has. If it has about 54-55 dB - you're in good shape then.
     
  2. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    Thing is, you have to figure the loading plus the loading of the MM phono preamp that follows.
     
  3. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Agreed. But we are talking about his particular phono, and we know what it is. He is also trying to not break the bank, and good SUTs are pricey. I think head amp checks a lot of boxes at sane money.
     
  4. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Ok, with 57 dB gain the MF has Copla's additional 9 dB will work just right and give him the suitable loading of 300 Ohm

    Sounds like a good contender
     
  5. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    No. You worry about loading on the SUT/head amp side, on the MM phono side the loading is standard 47000 Ohm
     
  6. Davey

    Davey NP: Portishead ~ Portishead (1997)

    Location:
    SF Bay Area, USA
    But now you are talking about connecting the Copla to the 100 ohm MC input, that won't work. You were making a lot more sense when recommending the Hagerman Piccolo as a replacement for the MC stage to get up to 66dB gain. Of course, it costs more than what he already paid for the MF preamp. Ideally, just return the MF and get a different model with higher gain. But agree, the Piccolo is a nice product.
     
    patient_ot likes this.
  7. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    Seriously???? The reason I picked up this wonderful Zesto SUT is because of it's wonderful flexibility. Probably the last SUT I will ever need and it sounds fabulous with a combination of 40 gain/loading settings. I have not found a cart that I can't match to it. If the OP had one this thread would never have started.

    [​IMG]
     
    hi_watt likes this.
  8. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Look at OP's budget please. You don't think I know about this one? I try to tailor my recommendation to fit people's budgets, not to just what I have or would like to have.

    Besides, how many others like this one do you know of?
     
    hi_watt likes this.
  9. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Good point, I got too excited.

    I could recommend an older model Pro-Ject Tube Box DS. Apparently amazon still has them for $399. Use the 40 dB setting with Piccolo's 26 dB, or 50 dB with Piccolo's 20 dB - see which works better. Plus, for when the OP buys other carts - that phono sounds very nice, quiet, and has MC loading adjustable on the front panel. I own one and run my Denon DP-60L with DL-110 cart on it - sounds great.
     
  10. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    3000 bucks for a box of switches and wires.
     
  11. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    the ifi iphono 2 should get him in the ballpark with the karat. never heard it but rave reviews and ostensibly a good value.
     
  12. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    What if I change my MM phono preamp to 100K or 62K or 38K etc.?
     
  13. avanti1960

    avanti1960 Forum Resident Thread Starter

    Location:
    Chicago metro, USA
    worth a try but man that is low output, about 7.5% output voltage of a typical CD player. linearity might be ok but dynamics wouod be a concern.
     
  14. It's really hard to make a stepup transformer that can accommodate all those front panel settings. The winding of such a transformer has to have many wires pulled out and wrapped around terminal posts. That's a lot of stopping and starting the winding machine. That's a lot of the costs of making such a device.
     
    Last edited: Jun 29, 2020
    jupiterboy and avanti1960 like this.
  15. FalseMetal666

    FalseMetal666 Forum Resident

    Location:
    Seattle, WA
    12x step up with the OP’s cartridge would yield about 1.8mV to the phono preamp.
     
  16. Ontheone

    Ontheone Poorly Understood Member

    Location:
    Indianapolis
    I've found the optimal gain setting in my system for a 0.5mV cart is 60dB. The beauty of the Zesto SUT is being able to try so many different combinations of gain and loadings to really dial in the sweet spot for a setting. It truly makes a huge difference. 58dB at 270 ohms vs 61dB at 180 ohms etc....Until you have the flexibility you truly don't know what you're missing. Plus my phono stage has 3 MM gain settings so you can now multiply the 40 settings on the Zesto SUT x3. It's a great value component for me even if others think it's a waste.
     
    morinix likes this.
  17. FalseMetal666

    FalseMetal666 Forum Resident

    Location:
    Seattle, WA
    All the Zesto stuff looks amazing - would love to own one of their phono preamps some day.

    Moving coil cartridges with outputs below 0.5mV and high native impedance (Denon, some Benz, some Dynavector) are difficult to match since they lose output just by virtue of their high impedance.

    OP needs a 1:30 (or so) ratio SUT to get around 5mV into the phonostage, but loading would be low at around 50 ohm.

    Seems like a headamp with lots of adjustability would be best, since 0.2mV and 30 ohm native impedance is kind of a difficult combo.
     
    Last edited: Jun 29, 2020
  18. nvilletele

    nvilletele Active Member

    Location:
    New City
    Lots more stuff being discussed here, and lot of different equipment suggestions. I am trying to keep up.
    Here’s where I am at the moment.

    I started moving my Technics amp to set it up with the Technics tt with the MF V90-LPS preamp. I’ll see how well it performs as per clercqie’s suggestion, but taking to heart avanti1960’s admonition re low output voltage.

    If it still seems unsatisfactory, I will think about what other equipment to purchase. I don’t think I will spend anything significant here. No $3000 unit for me. I’d rather sell the Karat cart and just use my MM AT15sa with the MF preamp.

    But the Piccolo at $249 is well within range. Though there was mention by Benzion of using it with the Pro-Ject Tube Box DS, that adds another $399 raising expenditures to around $650. And though no expert I, I have heard previously that tube preamps are best avoided.

    Is it not possible to use the Piccolo headamp with the MF V90 preamp I already have, as I thought was an option earlier discussed? That would seem the least expensive of the many wonderful suggestions so far. Is there any reason this would not be a fairly decent approach?

    If not, it looks like the ifi iphono 2 at $549 would be the next best way to go. That is doable for me, though at a higher just sold a cost I was hoping, and the $179 spent on the MF preamp would have been for naught, but I suppose I could always try to sell it. Not sure whether I can return it for a refund having already used it.

    (Still, I just sold a sax mouthpiece for $325 and perhaps I could sell a couple more to justify the extra bucks I may spend for the ifi or other unit.)

    Love all the suggestions and info you guys have so kindly provided and continue to provide.
     
  19. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    Piccolo would work fine with the phono pre you have now.
     
    Benzion likes this.
  20. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    I hear ifi suffers from reliability issues
     
    nvilletele likes this.
  21. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Why? The recommended loading for MM is listed as 47 kOhm on pretty much every phono and every cart. I will not pretend to know more than the people who build them.
     
  22. jupiterboy

    jupiterboy Forum Residue

    Location:
    Buffalo, NY
    The reason you might make that choice is to get a flat frequency response. My phono preamp has those choices. My point, however, is that you can do the math and IF you find a particular vintage transformer you like and need more options.
     
  23. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    I don't think it's a waste. In fact, I'd really like to own one, but if I am to spend 3 grand on gear, I will invariably spread it over several different items, rather than just one. I spend more than 3 grand a year on gear, but alwas in increments, and on variety. That's just me.
     
  24. Benzion

    Benzion "Cogito, ergo sum" Forum Resident

    Location:
    Brooklyn, NY
    Point taken. However, I don't thnk the OP is operating on that plain right now.
     
  25. nvilletele

    nvilletele Active Member

    Location:
    New City
    In the brief time I have just spent looking into it, I saw a number of comments to that effect. Makes one concerned.

    That is correct, for me, though of course technically I am not the OP of this thread, just of this particular issue.

    This is sounding so far as the best approach for me I have seen so far. (Go ahead, change my mind.). Still relatively low cost, and provides a lot of flexibility re gain choices etc.

    I just found a black cube se II for under $1000, but that has a fixed gain I think, and is still more expensive than I’d like to go unless I have to. I like the idea, in principle, of flexibility re gain and input impedance, though I do lack the experience and knowledge to really make the most informed decision.
     

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