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EL Amp II+ Balanced or Topping I50 from the anemic UMC404HD.

tiramisu

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I am having a bit of a conundrum. I'm using the UMC404HD audio interface, which has an excellent audio interface, good micro preamps, and inserts ( I do a lot of live conferencing and have a channel strip (DBX 286s) and an EQs in the sound chain). Where it sucks spicy banana peppers is on the outputs. They are anemic 2 volts rather than the 4 volts that I wish they were.

I have been using my trusty MDR-7506s for the last 20 years and being low impedance this has never been an issue. But now I'm thinking it would be nice to get a pair of HD600 (300ohms) or the cheaper drop HD6xx. I'm more of a diffuse field than Harman curve kind of guy.

First I thought I would just replace the interface, BUT... An interface with the same feature set as the UMC404HD with good outputs is about 4 times the price of my old UMC404HD. doh!
So my next thought was to go with a headphone amplifier and use the line out from the UMC404HD. I then found out from a review here that the darn thing outputs half the electricules needed to play with the big boys.

I did a bunch of reading here and elsewhere and after much confusion came up with the idea that the balanced output amps send more juice and are convenient from an audio interface (ignoring any noise improvements/degradations).

In the case of the EL Amp II+ Balanced JDLabs will double the gain as a special order ( wow I didn't expect that response from them, incredible customer service response) so that 2 volts will work with their AMP OR for the same price, I can order the Topping L50 that has the output gain to make up for my anemic audio interface.

I think (but am not sure) that I am probably better off going with the L50 from a specs perspective (but probably not an audible difference) and from a one-day being able to upgrade my audio interface to something with 4 volts out but I'm looking for confirmation from those who have already gone down this path.

Thanks in advance,
T
 

AnalogSteph

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Where it sucks spicy banana peppers is on the outputs. They are anemic 2 volts rather than the 4 volts that I wish they were.
Not even that much, actually. Specified maximum output is +3 dBu = 1.1 Vrms, and going by UMC202/204HD results you don't want to go past 0 dBu or so. The headphone output should manage a bit more (@Julian Krause got 2.4 mW into 600 ohms = 1.2 Vrms, along with so-so distortion levels even at 1 Vrms).

That's about all you get when your analog stage is running on +5 V single-supply and the opamps used aren't rail-to-rail output capable (both par for the course when it has to be as cheap as possible, and given that headphone output is even less than in the 202/204HD types, cost-cutting must have been a major concern). Run of the mill types generally get to about 1.2 V from either rail, which would mean only 2.6 Vpp ~= 0.92 Vrms maximum.

The L50 has 13.9 dB of gain to offer and the EL Amp II+ 13.5 dB - either should be enough to get HD600s to a sufficient level. They need about 2.5 V to hit 110 dB SPL, which was the already conservative target level recommended by NwAvGuy back in the day. If you aren't a loud listener, your needs may be 10 dB short of that.

If you are of the penny-pinching kind, an Atom Amp+ (gain 4.5x = 13 dB) or Schiit Magni Heresy (gain 5.5x = 15 dB) should get the job done, too. Both really decent amps in their own right and substantially cheaper (and with an output level control on the UMC404HD you should be able to evade any major volume pot channel imbalance issues). If you plan on eventually upgrading your interface and getting some IEMs as well, the L50 with its balanced input and -14 dB gain setting would be the more flexible option.
I did a bunch of reading here and elsewhere and after much confusion came up with the idea that the balanced output amps send more juice and are convenient from an audio interface (ignoring any noise improvements/degradations).
There are a few big IFs associated with that though.
1. You need a balanced cable for the headphones. I don't know how many aftermarket options can beat Sennheiser's stock cables for lightness and lack of microphonics.
2. Balanced outputs may provider higher gain and output level but it is by no means guaranteed.

Moreover, the typical advantages of balanced connections do not apply when the other end is a floating transducer.
 
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tiramisu

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Ordered a used L50 off of fleabay with the blind assumption it doesn't die a week after it arrives or isn't already NFG for the same price as the el amp II.
Getting a decent interface with inserts moves me all the way up to something like the Audient id44 MkII. I am feeling the slippery slope already buying an amp in order to buy a set of headphones and I would rather upgrade my voice channel strip, and get a proper parametric eq in the chain than buy a new audio interface first.

Got a new microphone and suddenly my entire rack needs to be replaced to take advantage of it.
 
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