SET amp owners thread

[joaovieira]

@joaovieira The amplifier section in your signature is empty. Are you moving on from Audiopax? If so, what have you decided on?

Hi Adam
I sold pre and amps from Audiopax.
I’m moving to APL HAS, to be available this year. It’s a Hybrid 400W amp.

HAS-MR - APL Hi-Fi

aplhifi.com

 

[LL21]

Hi Adam
I sold pre and amps from Audiopax.
I’m moving to APL HAS, to be available this year. It’s a Hybrid 400W amp.

HAS-MR - APL Hi-Fi

aplhifi.com

Very exciting! When do they arrive?

What were the deciding factors that led you to go for them over other flagship amps?

 

[joaovieira]

Very exciting! When do they arrive?

What were the deciding factors that led you to go for them over other flagship amps?

Hi LL21,
I own the streamer and the once flagship DAC from APL. And both raised very much the level of my stereo.
Than I became a very good friend of Alex Peychev, very kind person that owns APL.
His approach is very interesting, the way he “voices “ his gear is based on the sound of his Tape machine and his Turntable.
I decided to change everything here. Including the speakers.
I’m selling my Tidal Contriva G2 too.
And going all APL, to figure out if my stereo finally causes me goosebumps.
I believe that the ceramics drives and the diamond tweeter doesn’t make me feel like it’s real music. All these years I’ve been changing my digital (Lamp, Acqua, and finally APL).
APL will soon launch a new speaker with paper cones and silk tweeter. I had the chance to listen only by videos, but I’m going to Bulgaria probably this year to listen to that system on APL.
The sound seems to be pretty much what I’m looking for.
Hard to decide those things from here, without the chance to listen to many options.

 

[LL21]

Th

Hi LL21,
I own the streamer and the once flagship DAC from APL. And both raised very much the level of my stereo.
Than I became a very good friend of Alex Peychev, very kind person that owns APL.
His approach is very interesting, the way he “voices “ his gear is based on the sound of his Tape machine and his Turntable.
I decided to change everything here. Including the speakers.
I’m selling my Tidal Contriva G2 too.
And going all APL, to figure out if my stereo finally causes me goosebumps.
I believe that the ceramics drives and the diamond tweeter doesn’t make me feel like it’s real music. All these years I’ve been changing my digital (Lamp, Acqua, and finally APL).
APL will soon launch a new speaker with paper cones and silk tweeter. I had the chance to listen only by videos, but I’m going to Bulgaria probably this year to listen to that system on APL.
The sound seems to be pretty much what I’m looking for.
Hard to decide those things from here, without the chance to listen to many options.

Thanks! Exciting! Is this the Gravitas NB-MR (which says coming soon on the website?) or is this an entirely new flagship?

 

[joaovieira]

Th

Thanks! Exciting! Is this the Gravitas NB-MR (which says coming soon on the website?) or is this an entirely new flagship?

A new Flagship. It’s not in the website yet.
The name will be Endless.
Here is a review from Chris of Audiophile Style, who listened to the prototype.

A View And Preview Of New APL HiFi Speakers

At times, the joy that life attacks me with is unbearable and leads to gasping hysterical laughter. I find myself completely out of control and wonder how could life surprise me again and again and again, so completely. How could a man be a cynic? It is a sin. - Norm Macdonald October 17, 1959 - ...

audiophilestyle.com

 

[sjs]

I gotta a little tweak for the community here. It isn't the sort of thing everyone can do but OTOH its not complex and no soldering.

Most output transformers are held together by 4 bolts that go thru the corners of the transformer core. They often hold the end shells of the transformer on as well. These bolts are (or should be) insulated from touching the core by either fiber (on older transformers) or nylon shoulder washers. This is supposed to prevent the bolts from being a magnetic short to the magnetic field created in the output transformer by the power tube(s).

Those bolts are usually made of regular steel, mostly out of tradition. The thinking is the shoulder washers are doing their job.

That's not exactly true. Some of the magnetic field is able to induce energy into these bolts. Its not much, but especially with single-ended gear where every drop counts, it is measurable. I did an experiment over the weekend by simply measuring the output power, changing the bolts out for non-magnetic stainless bolts and measuring again. The output power went up by about 200 milliWatts. This might not seem like much but the amplifier I tried this on was only making 3 Watts. So about a 7% increase in power! The bolts cost 41 cents each at the hardware store.

I suspect, without talking to any OPT manufacturers, that they don't use stainless non-magnetic bolts because they think the steel bolts are working fine. I first discovered this issue 35 years ago working with toroid power transformers, which are usually supplied with a steel mounting bolt that goes thru the center hole. We found that bolt tended to run hot, considerably warmer than the transformer itself. In theory it shouldn't because the magnetic field in a toroid is very compact and tends to sit inside the core. In practice though, its sloppier than that and so the bolt was a magnetic short. Replacing it with non-magnetic stainless caused the transformer to run at a lower temperature.

This is the same idea. A word of caution: doing something like this, even though you might not have to open the amplifier up, could technically void the warranty, despite the fact that over time the output transformer will run at a slightly lower temperature. If the OPT is in sealed can there's nothing for it.

Back in the 90s we used to supply transformers for DIY, all the OPTs and Interstage transformers were made using brass bolts for this very reason, and they did sound better.
We also did not impregnate the OPTs or interstate transformers as you could always hear it, which by default tended to be polyester based.

 

[christensenleif@msn.com]

Back in the 90s we used to supply transformers for DIY, all the OPTs and Interstage transformers were made using brass bolts for this very reason, and they did sound better.
We also did not impregnate the OPTs or interstate transformers as you could always hear it, which by default tended to be polyester based.

if I don´t remember incorrectly, I had some of your transformers I got from Gary Dews of Borderpatrol...at least they had the same model numbers

 

[SVS]

Back in the 90s we used to supply transformers for DIY, all the OPTs and Interstage transformers were made using brass bolts for this very reason, and they did sound better.
We also did not impregnate the OPTs or interstate transformers as you could always hear it, which by default tended to be polyester based.

Using paper instead of polyester will give a much better effect than bolts.

 

[sjs]

if I don´t remember incorrectly, I had some of your transformers I got from Gary Dews of Borderpatrol...at least they had the same model numbers

You do remember correctly, I worked closely with Gary for a number of years

 

[sjs]

Using paper instead of polyester will give a much better effect than bolts.

I think you are referring to the seperation between winding layers, we used paper for that.
I was referring to the transformers being dipped, impregnated, or potted after build to reduce vibrations and noise and improve heat dissipation. The material used for this process becomes part of the sound of the audio tx in my experience.

 

[charles1dad]

@joaovieira
“APL will soon launch a new speaker with paper cones and silk tweeter. I had the chance to listen only by videos, but I’m going to Bulgaria probably this year to listen to that system on APL.
The sound seems to be pretty much what I’m looking for”

After all these years and all manner of driver/cone materials utilized, paper remains highly desirable and natural in its sonic presentation.Same for silk the other organic substance.
Charles

 

[SVS]

I think you are referring to the seperation between winding layers, we used paper for that.
I was referring to the transformers being dipped, impregnated, or potted after build to reduce vibrations and noise and improve heat dissipation. The material used for this process becomes part of the sound of the audio tx in my experience.

Yes, I mean the separation between the winding layers.

You are right, different varnishes affect the sound a lot. They increase the capacitance between the winding layers and this reduces high frequencies.
The best solution is to keep a strong tension on the wire, but this requires some experience. In this case, the transformer cannot be heard at low power, it can barely be heard at high power, but the speakers play much louder.

 

[adamaley]

As requested ! The amps could need a little more warm-up… just the main system here, no subs or super-tweeter.

Do you ever move the speakers further out into the room? If so, do you feel you lose soundstage depth having them up against the wall?

 

[bonzo75]

Videos Alert: Amp A vs B:

Which do you prefer? We had a clear in room preference.

 

[Scott Naylor]

Videos Alert: Amp A vs B:

Which do you prefer? We had a clear in room preference.

It’s pretty amazing the difference in how the amps handle surface noise on the record. I’m no expert on which sounds more natural with clicks and pops though.

 

[bonzo75]

It’s pretty amazing the difference in how the amps handle surface noise on the record. I’m no expert on which sounds more natural with clicks and pops though.

the videos were done at different times, I don’t have the video for one of the amps on that day, but message remains the same. The pops clocks has a different reason that is not relevant to the amp compare. As I said, message on the amp differences in that room would have remained the same

 

[cjfrbw]

Amp B was significantly better through my headphones and the maelstrom of You Tube compressions. More body, tone, flow, expansiveness. That doesn't mean it necessarily was the best live.

 

[Glide3]

It’s pretty amazing the difference in how the amps handle surface noise on the record. I’m no expert on which sounds more natural with clicks and pops though.

Videos Alert: Amp A vs B:

Which do you prefer? We had a clear in room preference.

B for me

 

[charles1dad]

Given the limitations of listening via my phone, amplifier B was better sounding by a clear margin. More engaging, natural and superior tonality.
Charles

 

[Fishfood]

Sun Audio SET being repaired (again). I'm trying out this no-name Chinese 300B with giant Tamura transformers. So far the sound is great. Cleaner than my Sun 300B. Generic 300B tubes only right now. I may need to pop in something good.