SET, Push Pull, or T-Amp best to drive Frugel horns?

[blue lander]

The Sure model looks cheap enough, I'll have to check it out. How does it sound at low volume levels? I barely need any gain to drive these speakers. Even with the 8wpc k-12g I rarely take the volume past 1/4th.

[kristleifur]

I have no experience with the Sures, only 41Hz amps with same chipset ... It's an interesting question / combo - I'd ask in the other thread specific to the Sures.

However, related to the purpose of driving fullranges - you might want to reduce the overall gain of the amp if you have SUPER efficient speakers, so as to bring the noise level down. They are quiet amps to begin with so it'd probably be a later-stage optimization.

[pjanda1]

I recently built a little amp with the Sure board, and I was happy with it. It didn't compete in any way with my tube amp, nor should it for the price. I can't compare it to other digi-amps, as I've never heard a 41hz unit and it has been too long since I had a Sonic Impact running.

IIRC, the only mod I did was replacing the input caps. DC offset was fine on my board and I left the LP filter in place. Depending on what you mean by "low volume", noise could be a problem. I used a fairly nice switching supply (the MeanWell that Sure was selling as a package deal). No matter where I placed them (amp and supply) in relation to each other, the amp had a decent hiss to it. My speakers (my own BetsyK's) are about as efficient as the A166's, and at very low levels, I could imagine the noise being obnoxious.

It is a really nice amp for the $$ though.

Paul
Wild Burro Audio Labs - DIY Full Range Speakers

[blue lander]

I still haven't found a proper power supply for the Sure, but I have been using it with a 24 volt 4 amp laptop power supply. That's on the low end of what the Sure board is supposed to work with, but the thing sounded a little unexciting and lifeless compared to a TA2020. I barely played with the thing, to be honest, I bet it has more potential if you provide it with sufficient voltage.

I also bought Arjen's 12au7 tube buffer and used it in conjunction with the TA2020 MK III board. While this didn't give the amp a "tube sound" by any means, it did sort of smudge the harsh edges off the T-Amp. It helps to hide that distinctive T-Amp sound a little so it sounds more like a conventional solid state amplifier. The only thing I don't like about it is that the tube doesn't really light up. They stuck a little LED underneath the tube to make it look like it does, which is a little lame in my opinion. Still, It's a great combination and I intend to keep it on hand for when I want a more clean, less lush sounding amp.

...then there's the Tubelab SE. This thing is in a completely different category than any other amplifier I've tried. It's far, far superior than the T-Amp or the K-12G or any other amplifier I've heard. It's one of those game changing components that makes you listen to all your favorite albums over again, sort of like going from MP3's to LPs or from a $50 cartridge to a $300 one.

It's the most articulate amplifier I've ever listened to. I'm hearing all sorts of minute details as well as slight variations in rhythm and pace I've never heard before. I'm finding out a well recorded album contains all sorts of nuances I never knew were there. You get a sense that the amplifier has complete control over the drivers. It's a perfect match for the A166, If you're hooking up a lesser amp to yours then you don't really know what your speakers are capable of.

It probably cost me $400+ to build so it isn't exactly fair to compare it to a $30 T-Amp or a $200 K-12g, but it's really taken my system to the next level and I don't think there's any going back. I'll keep Arjen's TA2020 though for when I get tired of tube lushness because it's such a clean sounding amplifier. I doubt the K-12g will ever be connected to my A166's again.

I highly recommend the Tubelab SE, but you do need to know a bit about how tube amps work to put it togeather. I don't, so I had to rely on help from other people on DIYaudio. It's more than just stuffing parts into a PCB and powering it on, the directions assume you know what you're doing. For instance, it just says "Connect the transformer to the PCB" rather than "solder the green wire to throughhole X, solder the red wire to throughhole Y, etc." If you understand the circuit it's obvious what wire goes where, but if you don't (or you aren't 100% sure), you're going to need somebody's help. This isn't criticism, the Tubelab website states clearly that this amp isn't for beginners. It's just something to keep in mind. They do offer a Tubelab Simple SE which looks much simpler to build, and the instructions hold your hand through every step.

I'm thinking of building a F1 or F2 next, since they supposedly mate well with single driver speakers. I've read the F2 has a tubey sound to it that's probably more to my liking, but I may build the F1 since I want to bring something new to the table rather than just another tube amp. I also looked at building an OTL tube amp, but I think that's a little over my head at this point.