3e Audio A7 [TPA3255 PFFB Stereo] Finished Amplifier - User Impressions | Owner's Thread

[somebodyelse]

If people think it sounds better, and they can afford it, what is wrong with that? I happen to think speaker cables and interconnects are important. I get that spending £3500 on balanced interconnects and similar on speaker cable isnt for everyone, and that almost certainly you don’t get £3500 worth of improvement, but it’s my money and if it gives me pleasure and satisfaction, then so what?

You can diss it all you like but I am very satisfied with the equipment and alleged snake oil products I have in my system and I would buy them all over again if I had to do it again. I think paying £ 1 million for a Banksy scribble is worthless, but if it means something to the buyer then good luck to him/her

Buy an expensive watch and you won't get many arguments about your right to do so. Tell people that you seriously think it keeps better time than a cheap phone synchronised to network time and they'll know you're delusional.

 

[astamixa]

Hello everyone! Excuse my pidgin English. It's not my native language.
In January 2025, I received two 3e Audio A7 mono amplifiers (first generation). I've been using them for a year now. My setup is as follows: a fanless mini PC, Intel N100, Windows 11, Foobar2000, SMSL DO300 DAC, SMSL HO200 preamplifier, two 3e Audio A7 mono amplifiers, and System Audio SA Saxo 40 speakers. To keep myself busy, I built two 48V, 400W power supplies. I purchased A-D-P40048-U1 48V, 8.3A switching power supply modules with APFC on an aluminum chassis for passive cooling from AliExpress. For better cooling, the silicone gaskets on the power elements were replaced with aluminum oxide ceramic ones. The input and output filter Indian-made capacitors of power supply were replaced with Japanese Rubycon and Matsushita capacitors (FC 820 μF*63 V with a high ripple current of 2670 mA, three in parallel), bypass with high-voltage, thermostable C0G ceramic capacitors, 100 V, to control high-frequency interference. High-frequency ripple at the power supply output at 25-50% of the nominal load is less than 60 mV. Cases for installing the power modules, as well as all the necessary connectors, switches, and cables, were purchased. The modules are attached to the bottom of the cases via a thermal interface, which transfers heat to the outer case, minimizing heating. Power supplies work very well by providing excess current. And I had a great time.
Thanks a lot @3eaudio for the great work!
Best wishes, Kos

 

[Raiju]

After a week I opened my A7 stereo to change roll opamp.

I couldn't help but notice that you run your Burson V7's at 36V. They are rated for 30V, given the discrete parts I am sure they work fine and the 30V by the manufacturer is mainly for thermal reasons. Since they run 60–70°C at 30V I was wondering if you had some heat issues? You are still active so you should see this and maybe short jumper J30 for longevity?

 

[fredreadrick]

I couldn't help but notice that you run your Burson V7's at 36V. They are rated for 30V, given the discrete parts I am sure they work fine and the 30V by the manufacturer is mainly for thermal reasons. Since they run 60–70°C at 30V I was wondering if you had some heat issues? You are still active so you should see this and maybe short jumper J30 for longevity?

So far I did not encounter any issues.

 

[harkpabst]

So far I did not encounter any issues.

Longevity is not a short-time issue by definition.

Given the price of these Burson opamps I agree with @Raiju that shorting the jumper J30 is probably a good idea. +/- 15 V is the rated typical supply voltage, close to the specified maximum of +/- 16 V. The minimum supply voltage is as low as +/- 4 V (which might still work in this configuration).

Running these opamps at +/- 18 V only creates additional thermal stress without providing any benefits. It will also most likely void your warranty.

 

[CJV-NWA]

New owner 3e A7 (stereo) w/48V. I have a very nice switch so I am evaluating the A7 "side-by-side" my AVR (Yamaha RX-A4A). The A7 is connected by RCA to the preamp outs Front on my AVR. I only listen 2.0..

First issue is lower sound level versus AVR, which I understand to be related to sensitivity. Before I can truly pass judgment on SQ using the ear test, I need to get the volume from the A7 as high as possible to get nearer the AVR. I did so by clicking the "Bypass Vol" switch to the right, dialing the Volume knob to Max, and clicking the "RCA Gain" switch to the right, to High.

My question concerns distortion. Did any of these decisions themselves introduce distortion?

 

[TurtlePaul]

My question concerns distortion. Did any of these decisions themselves introduce distortion?

No. The A7 will still have much less distortion than an AVR regardless of volume bypass or RCA gain settings.

 

[3eaudio]

@CJV-NWA is your AVR more than 30dB gain or even higher?
with RCA Gain set high the Gain will be close to (26+3)29dB.

 

[harkpabst]

I did so by clicking the "Bypass Vol" switch to the right, dialing the Volume knob to Max, and clicking the "RCA Gain" switch to the right, to High.

The "Bypass Vol" switch is actually a "Bypass | Volume Control" switch. It probably won't make a difference in practice, but to make sure you're getting the maximum output you should flick the switch to the left, putting the 3E AUDIO A7 in bypass mode. The potentiometer is bypassed then, ensuring that the volume control knob has no effect and the signal path is as short as possible.

The RCA Gain switch only makes a difference when using thes single-ended RCA inputs, not the balanced XLR inputs. But I guess, you figured that.

Unfortunately, getting the volume "nearer to the AVR" won't buy you much when comparing the sound quality. It is commonly accepted wisdom that for a fair comparison you must match the level between two devices to much less than 1 dB. Some say less than 0.3 dB. If you don't, then your brain will play tricks on you, always preferring the louder presentation. This happens on a subconscious level, so even if you know about the effect it's almost impossible to ignore it. Not sure how your entire setup will look like for the comparison, but you really need to find a way to match the levels as closely as possible.

Like @TurtlePaul I have no doubts that the A7 technically betters almost all AVRs ever made.

 

[peng]

Such Yamaha AVR typically has 28-29 dB gain so with the A7 volume control on bypass, gain set to high, the two should be level matched within +/- 0.5 dB.

 

[CJV-NWA]

The "Bypass Vol" switch is actually a "Bypass | Volume Control" switch. It probably won't make a difference in practice, but to make sure you're getting the maximum output you should flick the switch to the left, putting the 3E AUDIO A7 in bypass mode. The potentiometer is bypassed then, ensuring that the volume control knob has no effect and the signal path is as short as possible.

The RCA Gain switch only makes a difference when using thes single-ended RCA inputs, not the balanced XLR inputs. But I guess, you figured that.

Unfortunately, getting the volume "nearer to the AVR" won't buy you much when comparing the sound quality. It is commonly accepted wisdom that for a fair comparison you must match the level between two devices to much less than 1 dB. Some say less than 0.3 dB. If you don't, then your brain will play tricks on you, always preferring the louder presentation. This happens on a subconscious level, so even if you know about the effect it's almost impossible to ignore it. Not sure how your entire setup will look like for the comparison, but you really need to find a way to match the levels as closely as possible.

Like @TurtlePaul I have no doubts that the A7 technically betters almost all AVRs ever made.

Thanks for explaining the switch- the "doc" was not helpful.

Simultaneous back/forth:

..........--> AVR Pre Int --> low into AVR Amp --
Source --|.................................... |--> high into (passive) Switch --> high into Speakers
..........--> AVR Pre Out --> low into A7 Amp --

Also, the Auto-On/Off works great.

I left it on for 5 hours, not at a high volume per se (TV was source) and it did get warm. Neither my AVR nor the switch did. The A7 seems very solidly built (affirms the research I did pre-purchase) and I'm going to assume it will run warm without issue.

 

[CJV-NWA]

I'm "warming up" to the A7's sound. I was thinking it was "thin" but it may be accurate. The A7 allows me to unplug the ports on my speakers to extend my listening to lower frequencies (they are "boom-y" with the Yamaha's built-in amp).