Which affordable amp for a low impedance HP?

[sguyader]

Hi,
I purchased a Verum 1 HP, which is rated around 7 ohms. I use it in a home studio environnement where I need a pretty neutral/analytical sound. When I plugged it I to my interface (Presonus 1824c) I found the sound a bit unimpressive, lacking in bass. Checking the 1824c specs and reviews, I found that it's HP output has a pretty high impedance, which could point to a mismatch with the Verum 1.
S, I purchased a Topping L50 which looked to fit the HP needs, or it was my impression. Unfortunately the L50 quickly failed, or maybe it's just the AC/AC power brick but I can't test the amp with another adapter as AC/AC is hard to find (going to return the unit to Amazon).
My questions are:
- Was I just unlucky with that unit, or did the 7 ohms impedance HP draw too much current for that power supply, or something like that?
- In this case, should I purchase another, more powerful, HP amp?
- would something like the Topping A30 pro, SMSL SH-9, be better suited?
- Something else to consider below 300$, preferably with balanced input? (The TRS I/O passthrough of the L50 was really cool for my studio setup).
Thanks for reading.

 

[Dunring]

I've had the L50 a bunch of times and there's a failure rate on everything. I'd stick with it and get a replacement. The E50 is a great DAC too if you ever match them up. If you reorder from Hifi-College on Amazon, I just got a different Topping amp (A30Pro) and it had a card in it for a free warranty 1 year extension. I emailed them the serial number and they replied quick about it.

 

[sguyader]

I've had the L50 a bunch of times and there's a failure rate on everything. I'd stick with it and get a replacement. The E50 is a great DAC too if you ever match them up. If you reorder from Hifi-College on Amazon, I just got a different Topping amp (A30Pro) and it had a card in it for a free warranty 1 year extension. I emailed them the serial number and they replied quick about it.

Thanks. I know that every device can fail more or less quickly. I just wanted to make sure that my 7 ohms HP is not what could have caused a premature failure of the power supply.
For now I don't need a DAC, I use my Presonus interface for DAC.
May I ask why you got the L50 "a bunch of times"?

 

[Dunring]

Thanks. I know that every device can fail more or less quickly. I just wanted to make sure that my 7 ohms HP is not what could have caused a premature failure of the power supply.
For now I don't need a DAC, I use my Presonus interface for DAC.
May I ask why you got the L50 "a bunch of times"?

I buy and sell about $6k a month in audio equipment, so I get the same things several times. The only problems I had was buying a used one from Aoshida on Amazon and the power brick was loose in the box and rattled, and the other was in protection mode, so they both went back. They sent me six amps and DACs in protection mode last year, all separate orders one after the other. Hifi-College stuff always works, and they offer the extra year warranty. If you got it new you should be fine and it was just bad luck. Computer components and audio equipment has a 1-2 percent return/defect rate usually.

 

[sguyader]

I have my eyes on this one. What do your think would be the benefit of the A30 Pro over the L50? Would the benefit be worth the difference in price?

... I just got a different Topping amp (A30Pro) ...

 

[Dunring]

They both have low noise for IEMs and the L50 is enough for Beyerdynamic 600ohm easily. The A30Pro can handle the Hifiman he6se with a balanced dac, but if that's not the plan, the E50 runs cooler and can power almost anything. Both have the same power on all plugs, so you can save a bundle on cables either way.

 

[sguyader]

They both have low noise for IEMs and the L50 is enough for Beyerdynamic 600ohm easily. The A30Pro can handle the Hifiman he6se with a balanced dac, but if that's not the plan, the E50 runs cooler and can power almost anything. Both have the same power on all plugs, so you can save a bundle on cables either way.

Those headphones you cited have a higher impedance than mine, though.

 

[sguyader]

The A30Pro can handle the Hifiman he6se with a balanced dac, but if that's not the plan, the E50 runs cooler and can power almost anything. Both have the same power on all plugs, so you can save a bundle on cables either way.

Did you mean "L50" instead of "E50"?

 

[NiagaraPete]

E50 runs cooler and can power almost anything. Both have the same power on all plugs,

That’s only the case if you run the A30Pro at low gain settings. When the volume is 3/4’s it barely gets warm.

 

[Dunring]

That’s only the case if you run the A30Pro at low gain settings. When the volume is 3/4’s it barely gets warm.

Yep in low gain with something like IEMs I measured 105f with a laser thermometer. The silver ones run cooler than the black coated ones, had both a couple of times.

 

[NiagaraPete]

Yep in low gain with something like IEMs I measured 105f with a laser thermometer. The silver ones run cooler than the black coated ones, had both a couple of times.

Yeah they run in a class A mode at Lowe levels.

 

[IAtaman]

It feels intutive that it will be harder for an amp to drive a lower impedance load than a higher one, but it is actually quite the opposite. Since HPAs are designed (ideally) to supply the same voltage regardless of the current, driving lower impedance loads is actually harder on them.

L50 specs list power as low as 16ohm and Amir tested them down to 12ohm so it is not absolutely clear whether 8ohm is within specs for L50. I know for a fact that they can drive 10ohm headphones with no issues however and according to the specs of your headphones it would require around 100mA to reach 115dbSPL so I think L50 would be fine.

 

[ddaudio]

There's also the Sabaj A10h which @amirm tested down to 12 ohm with no sign of strain, don't know if it can go further?

 

[shuppatsu]

Did you get the headphone stand?

 

[Dunring]

There's also the Sabaj A10h which @amirm tested down to 12 ohm with no sign of strain, don't know if it can go further?

I've had the Sabaj A20h with 10 ohm IEM's and never had an issue running them in low gain, they sounded great. Haven't been able to find measurements, but I had three of them at one point and tried them on everything up to the He6se. The only annoying thing is the plugs are all in the back, and XLR plugs are face upside down (the DAC they discontinued, the A20D would sit on it and they would line up).

 

[sguyader]

Thank you guys. I think I'll reorder the L50, as I was satisfied with it's operation, and I found it's balanced passthrough I/O capability very convenient for my studio needs: I can have the L50 between the Presonus interface and my monitors, and choose what I want to listen through using the same interface outputs.
Though, the A30 Pro is tempting...

 

[sguyader]

Since I leave in the Caribbean, sending the L50 back to Amazon Europe is quite expensive and it might not be worth it, especially if it's just the power brick that is faulty. Finding a 15V AC/AC power brick is quite hard for where I leave. I found a 16V/1A, do you guys think it's okay for remplacing the 15V/1A from topping? Or is that extra 1V risky for the L50?

 

[AnalogSteph]

Honestly I find it hard to believe that a dumb transformer power brick would be faulty to begin with. There's basically nothing in them that can go bad save for the thermal fuse, and with few exceptions killing that requires gross overloading. I would procure a multimeter and test for output voltage. I'd expect about 18 VAC unloaded.

 

[sguyader]

Honestly I find it hard to believe that a dumb transformer power brick would be faulty to begin with. There's basically nothing in them that can go bad save for the thermal fuse, and with few exceptions killing that requires gross overloading. I would procure a multimeter and test for output voltage. I'd expect about 18 VAC unloaded.

I have a multimeter and I tried to test the output voltage already. I get 0 VAC. I'll try and open it and see if there's a blown fuse. The power strip it was plugged in is behind a power conditioner, so I think the incoming power was fine. Regarding gross overloading, that's why I asked if my 7 ohm headphone could be drawing too much current (amperes) and lead to 9 overloading. Before the amp stopped working, I heard a few clicks, the same relay clicks as when I turn on the amp.

 

[solderdude]

Measure the DC resistance on the input and on the output side of the wall wart.