Anybody running TPA series Class-D amps? (3116, 3251, etc.)

Discussion in 'Solid State Gear' started by jhoyt, Dec 31, 2017.

  1. 34VAC rectifies up to 48VDC. Just right for the TPA3255, if you wanted to run a TI evaluation board.
    opa1 likes this.
  2. That amp is based on the TAS5615 chip. Not quite the same, but still a good performer.

    Here is the page for the TPA3251 evaluation board: The price is $149, but they have a recurring promotion (code: highpoweraudio) for 50% off. This makes it a VERY good price, imho. If I had a few bucks to rub together I'd pick one up for myself.
  3. inthewoods

    inthewoods AARP Member

    Thanks. Now I have these boards coming out my ears. Time for a shootout I suppose. Code didn't work
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  4. opa1

    opa1 Moderator Staff Member

    I tried my TPA3116D2 with the Vali 2 as a preamp this morning. The touch of the tube warmth really is nice. It's much better than I thought it should be. Might have to explore this a little farther.
  5. The TPA3251 with the Saga, and it's tube buffer, sounds amazing. I highly recommend this exploration!
    TubeHiFiNut likes this.
  6. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    This is a finished product or "some assembly required"? ;)
  7. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    @jhoyt - Have you listened to the TPA-3250 based amps?

    And do you have a good source for the "plug and play" TPA-3251 based amp you referenced?
  8. I have not had the opportunity to listen to the TPA3250 amp that is currently on the market. However, there is quite a bit of talk about it right now on AK's "TPA3116 vs. the Tripath" thread. Seems to be well thought of, just needs the proper power supply voltage to work its best.

    I've recently been looking for the 3251 amp that I have, but the manufacturer seems only interested in selling in large lots. However I haven't specifically inquired about onesies and twosies. The manufacturer is at, their web store is

    My amp is the G3H, which is sold as a bare board *or* complete with enclosure.
    TubeHiFiNut likes this.
  9. I just emailed the manufacturer, to see if he will sell individual amps, instead of bulk lots. We'll see. Maybe I'll become the North American importer... :D
    ejfud and TubeHiFiNut like this.
  10. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    Thank you @jhoyt :)
  11. inthewoods

    inthewoods AARP Member

    One of these ought to control my woofers. One is a Class D Audio, the other TI. DSC_0203.JPG DSC_0204.JPG
    jhoyt likes this.
  12. inthewoods

    inthewoods AARP Member

    And I have a Meanwell SE-600-36 to power these.
  13. @inthewoods, VERY nice! Which TI board is that? Looks like the 3251?
  14. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    I'm intrigued by the Schiit Saga. Seems reasonably priced at <$400. Lots of inputs.

    Please tell me more. :)
  15. rogerfederer

    rogerfederer Junior Member

    i really like the sound of the TI 3250 evaluation board. had to make my own enclosure and using battery power.
  16. They're very simple, in function. The foundation is a 64-step stepped attenuator that is relay controlled. So when you change volume you can hear the relays clicking. The nerd in me likes it, the aesthetist in me does not (nerd wins). There are four single-ended inputs, again relay controlled. Two sets of outputs. The "option" is the switchable tube buffer. The unit takes a twin-triode 6SN7 or variant. The stock is a Russian 6H8C tube, which is somewhat dry. I'm running a Shuguang Treasure CV-181Z which is rich sounding, without being overly so.

    When switched out, the preamp functions as a simple passive, with only a couple SMD resistors (and attendant relays) in the signal path. With the tube switched in, there is an increase in volume, but it is barely perceptible. Maybe the equivalent of one click of the volume knob. For all practical purposes the tube is a unity gain buffer. Even though volume is barely affected, I can tell a distinct improvement in the depth and tangibility of sound. It pairs very well with the absolute transparency of the TPA325x series of amplifiers.

    Moving up the Schiit chain to the Freya (which I only know of through research) you get 20dB-ish gain through 4 6SN7 tubes or a JFET buffer stage. There is also an option to run as a simple passive. The volume control is the same relay switched affair, but with 128 steps. It has balanced inputs and outputs, as well as single-ended. It sells for $699, or double the Saga.
  17. inthewoods

    inthewoods AARP Member

    Correct, 3251. PS arrived in non-working condition. New unit on the way.
  18. TubeHiFiNut

    TubeHiFiNut Administrator Staff Member

    Does anyone know which aftermarket power supply works best with the NFJ&FX TPA-3250?

    Mine has shipped and should be here in a couple of weeks.

    Also thinking about grabbing one of the Schiit Saga preamps @jhoyt uses.

    Definitely an interesting combination.
  19. inthewoods

    inthewoods AARP Member

    Lots of watts here and these sound great. DSC_0001.JPG DSC_0001 (2).JPG
    opa1 likes this.
  20. Great to hear! Those are some good looking amps.

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