Suca Audio U7 aka Aoshida A7 aka Nobsound H7 aka Douk Audio H7 tear down

[shpong]

TPA3255 base amplifier with xlr input. Suca Audio U7 or other models with similar chassis . Got it from aliexpress around $87. This amp is the cheapest of all 4.

 

[shpong]

Reservoir capacitor , the 5 green , is Samxon GF capacitor 820uf 50v high ripple , low impedance 105

 

[shpong]

Other supplies , the black 8 , are Lelon capacitor RXK 470uf 16v Low ESR 105

 

[shpong]

DC blocking input cap are ceramic SMD pararelled with MKT Epcos 1uf 63v.

 

[shpong]

Except 4 DC blocking input capacitor to TPA3255. It is just only 1 uf with leftover area of SMD. According to TPA3255 manual , it should be at least 10uf.

 

[MCH]

Thanks for sharing shaping.

For that price with balanced inputs, it could be a very interesting one... If it had a master volume control!!!

Are you capable of measuring the outputs when both channels are maxed to see if at least they got the balance right?

 

[shpong]

It has Lt. and Rt volume control but I only use my ears to adjust the balance. Actually I use it as one of my 4 amps in active 4 ways speakers because it has xlr.

Thanks for sharing shaping.

For that price with balanced inputs, it could be a very interesting one... If it had a master volume control!!!

Are you capable of measuring the outputs when both channels are maxed to see if at least they got the balance right?

 

[shpong]

Sadly , last night it burn one of my tweeter because of electrical surge.

 

[shpong]

Sadly , last night it burn one of my tweeter because of electrical surge.

Don't misunderstanding. The amp is as good as it should be for the price or better but I think the power supply does not have soft start. The electric has down for 1 second and suddenly surge up. I was always warned that I should have a 10-20uf cap series to the tweeter but the thing went well so I carelessly removed the cap.

 

[Charger]

I have this amp (the Douk H7) along with the preamp (H8). Thanks for the pics of the guts.

What are we seeing here? Is there two chips or just one? Is it a true "balanced" design. Or does balanced just mean the XLR outputs.

I'm pretty happy with mine, it's maybe a bit harsh with my source being digital (topping d10 balanced DAC).

 

[shpong]

I have this amp (the Douk H7) along with the preamp (H8). Thanks for the pics of the guts.

What are we seeing here? Is there two chips or just one? Is it a true "balanced" design. Or does balanced just mean the XLR outputs.

I'm pretty happy with mine, it's maybe a bit harsh with my source being digital (topping d10 balanced DAC).

I agree with you on a little harsh sound. I changed the red wire to the binding posts with furutech cable and filled/replaced ceramic SMD cap with 10uf Nichicon muse BP capacitors and it went well.

 

[ThsM]

 

[mhardy6647]

I am always so glad to see a single VU meter on a piece of stereo equipment.

 

[Charger]

That's a fair review, and he talks about the harshness in the top end.

I've retired my H7 and have reverted back to a SMSL AO200, and have welcomed the return of that much warmer sound.

 

[arancano]

I agree with you on a little harsh sound. I changed the red wire to the binding posts with furutech cable and filled/replaced ceramic SMD cap with 10uf Nichicon muse BP capacitors and it went well.

I'm trying to take the lid off the amp. Have all screws off and comes out to the point where the tabs on the XLR connectors block the exit. Is there a trick to getting it all the way out? I'm trying to see if it has a replaceable op amp so I can put on a Starkos.

 

[shpong]

I'm trying to take the lid off the amp. Have all screws off and comes out to the point where the tabs on the XLR connectors block the exit. Is there a trick to getting it all the way out? I'm trying to see if it has a replaceable op amp so I can put on a Starkos.

Firstly , unscrew the front panel then detached the vu meter cable off. There is 4 smd 5532 op amp. It is very tiny so I think it is unreplacable with Starkos. I do replace the 5 Samxon 820uf/50v capacitor with Elna silmic2 100uf/63v which fit in perfectly but 8 times less than the Samxon and replace 8 Lelon 470uf/16v with Elna silmic 47uf/16v. More bass!!!