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Burson Soloist 3XP Review (Headphone Amp)

Rate this headphone amplifier:

  • 1. Poor (headless panther)

    Votes: 152 65.0%
  • 2. Not terrible (postman panther)

    Votes: 66 28.2%
  • 3. Fine (happy panther

    Votes: 5 2.1%
  • 4. Great (golfing panther)

    Votes: 11 4.7%

  • Total voters
    234

Wegi76

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Guys, I could really need some advice (electrics noob). The DC-Offset topic concerned me and I just grabbed a multimeter and measured the volatage between pin 2 and 3 of the male xlr-preouts on the back.

Since I powered it on about 15 minutes ago the values constantly creep up and seem to stabilize around -137mV on the left and -97mV on the right channel. Is this something to worry about? Directly after powring on, it shows positive values, crosses zero pretty fast and then continues to drift into negative values.

I cannot stick those "measurement needles" (don`t know the english word for them) into the female balanced headphone out directly, because the isolation is too thick but on the other side of a 4-pin-xlr to 3,5mm jack it only reads 9mv on one channel and 15mV on the other, so much lower values. uCorrection below. Also big offset here... (-128mV, -81mV) With out put set to pre-out, it has a slight positive offset.

Any advice, if I need to be concerned? Thanks!
 
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solderdude

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Any advice, if I need to be concerned? Thanks!

Can you measure both for L and R between hot(pin-2) and ground (which is pin 1) and cold(pin 3) and ground ?
I assume you measured between pin 1 and 2 ?

We are assuming here that the DC-offset on the XLR outs is the same as on the headphone out. (there seems to be an extra buffer in the XLR out)
 

Wegi76

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Hey there,

I measured between pins 2 and 3 as labeld in right representation ("Männlich") below. I`ve just switched it on again and will repeat the measurements between the other pins as you asked for in about 15minutes or so, when it stabilized.

Thanks already!





1653815887433.png
 

Caliban

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Guys, I could really need some advice (electrics noob). The DC-Offset topic concerned me and I just grabbed a multimeter and measured the volatage between pin 2 and 3 of the male xlr-preouts on the back.

Since I powered it on about 15 minutes ago the values constantly creep up and seem to stabilize around -137mV on the left and -97mV on the right channel. Is this something to worry about? Directly after powring on, it shows positive values, crosses zero pretty fast and then continues to drift into negative values.

I cannot stick those "measurement needles" (don`t know the english word for them) into the female balanced headphone out directly, because the isolation is too thick but on the other side of a 4-pin-xlr to 3,5mm jack it only reads 9mv on one channel and 15mV on the other, so much lower values.

Any advice, if I need to be concerned? Thanks!
If I remember this right - when I played around with the offset pots on my Soloist, I could only adjust the offset for the headphone outs, not the preamp out. The blue pot adjustments perhaps only affects the power stages, don´t know of any other adjustments.
It all ended up swapping those fancy Burson homebrew OPs for the supplied 5532s to get decent (and relative stable) offset readings on the preamp outs.
Sound was however ok both in preamp and headphone mode, very powerful (which is why I bought it) a bit noisy as some has pointed out.
But this drifting offset thing told me that this is a bad design.
Things you take for granted when you buy a device like this are obviosly not applicable here.
Glad I sold it. Had not bought it if this review had been posted earlier.
 
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Wegi76

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Can you measure both for L and R between hot(pin-2) and ground (which is pin 1) and cold(pin 3) and ground ?
I assume you measured between pin 1 and 2 ?

We are assuming here that the DC-offset on the XLR outs is the same as on the headphone out. (there seems to be an extra buffer in the XLR out)

Here you go...

DC between PinsLeft channelRight channel
2-3-137mV-97mV
2-1-71mV-51mV
3-166mV46mV

And a big correction! When measuring the headphone cable, the amp was still in pre-out mode.

After changing that it reads -128mV (left channel) and -81mVa (right channel) :-(
The resulting values are exaclty the differnce between the slight positive offset when the amp output was set to pre-amp and the negative offsets measured above.
 
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AudioSceptic

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Learning to be a good electronic designer can take decades, and yes this process of studying the behaviour in OP amps can be part of this. Among many other experiments, you don't go and read an electronic for Dummies book and design a great amp.
Point taken, but spending >$1000 on this for that reason doesn't make any sense, does it?
 

PeteL

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There are speaker amplifiers much more powerful than this one which is orders of magnitude quieter and cleaner. Just because it is powerful doesn’t mean it has to lack on everything else. There’s no technical need. The designer is simply incapable.
I did not say it was a fatality, but why would that matter if the owners don't hear any of those flaws with the headphones they have? And why compare to speakers amplifiers? I don't no anybody who would purchase that to drive speakers. Again, as Amir's pointed out, it's a very niche Item, I don't say go and buy that, I don't say it's a sound purchase, I am saying that it's not necessarily easy to find a more powerful headphone amp than this. I don't know how the others 5W+ headphone amps measure.
 

sarumbear

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I did not say it was a fatality, but why would that matter if the owners don't hear any of those flaws with the headphones they have? And why compare to speakers amplifiers? I don't no anybody who would purchase that to drive speakers. Again, as Amir's pointed out, it's a very niche Item, I don't say go and buy that, I don't say it's a sound purchase, I am saying that it's not necessarily easy to find a more powerful headphone amp than this. I don't know how the others 5W+ headphone amps measure.
If you need more than 5W, use a Topping PA5. It cost $349 instead of$1200.
 

solderdude

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Here you go...

DC between PinsLeft channelRight channel
2-3-137mV-97mV
2-1-71mV-51mV
3-166mV46mV

And a big correction! When measuring the headphone cable, the amp was still in pre-out mode.

After changing that it reads -128mV (left channel) and -81mVa (right channel) :-(
The resulting values are exaclty the differnce between the slight positive offset when the amp output was set to pre-amp and the negative offsets measured above.

128mV DC offset is quite high. Around a few mV would be better.
A confounding problem seems to be that the DC offset changes from being cold to warmed up.
A 16ohm headphone would dissipate 1mW even when there is no signal.
This won't burn out any headphones though.

Is that DC also volume control dependent (no signal into the amp) ?
 

PeteL

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If you need more than 5W, use a Topping PA5. It cost $349 instead of$1200.
You mean modifying your headphones and connect them to the speaker posts? Has it been measured in 300 ohms and such?
 

Wegi76

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Is that DC also volume control dependent (no signal into the amp) ?

No, it does not seem to be volume dependant at all.

I opened the case and (headlessly!) tried to figure out how the 4 blue pots work and finally managed to reduce the DC offset a bit.

Now it reads -98mV left and -63mV right on the headphone out. Pre-Out readings remained identical, like the owner said somewhere above. I did not mangage to get anywhere close to 0 when playing with the pots :-/ Really start disliking the amp...

BTW... When the case is open and there is air movement the readings start to jump around, if you breath air onto the pcb the DC reading eaisly varies around 100mV or so... It seems like something inside is real sensitive to temperature
 
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sarumbear

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sarumbear

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i thought (may be incorrectly) the pa5 cant handle headphone impedance?
Headphones almost always have higher impedance than speakers.
 

solderdude

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No, it does not seem to be volume dependant at all.

So it is the discrete output stage that is the problem.

I opened the case and (headlessly!) tried to figure out how the 4 blue pots work. I managed to reduce the DC offet a bit.

Now it reads -98mV left and -63mV right on the headphone out. Pre-Out reading remained identical. I did not mangage to get any close to 0 when playing with the pots :-/

Each channel has 2 amplifiers. When using a TRS plug only 2 or the 4 amplifiers supply a signal.

The pots, most likely, ar DC offset adjustment potmeters, they could also adjust the idle current but this is unlikely.

These pots are multiturn (20 turns and have no end stop so you can rotate indefinitely. You will hear a slight 'tick' when the end of the adjustment range is reached) so it may require more than just a small adjustment to get the DC close to 0.
When it is a really crappy design it may never reach 0mV.

1 pot will adjust the +L and another -L and the other 2 are for R+ and R-
You would have to figure out which pot adjusts which of the 4 channels (L-, L+, R- or R+) opposite ground (pin 1 on the 3 pin XLR)
Note the 4 pin XLR does not have a ground so use pin 1 from one of the XLR-3 pin connectors.
within +/-10mV is good enough when fully warmed up b.t.w. no need to adjust it within a few mV.

EDIT: I found this pic which is helpful.
channels.png



Pre-out may well have its own circuit (the opamp close to it).
 
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Wegi76

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Thanks again for your help, solderdude. I`ll try to look at this a bit less headlessly tonight when I have time again. :)
 

PeteL

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Headphones almost always have higher impedance than speakers.

In theory the PA5 as about the same power delivery as this Burson, but it was not designed for headphones. Off the bat it won't work with regular unbalanced headphone cables, you will need two negative leads.
DC offset considerations have to be checked too. All agreed that more power can be delivered with less noise and distortion, but why compare Apples and Oranges?
 
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Veri

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In theory the PA5 as about the same power delivery as this Burson, but it was not designed for headphones. Off the bat it won't work with regular unbalanced headphone cables, you will need two negative leads.
DC offset considerations have to be checked too. All agreed that more power can be delivered with less noise and distortion, but why compare Apples and Oranges?
Problem with power amp is that if you make a mistake and feed it too high output resulting in catastrophic power you might break a headphone. But other than that it you're careful you should be able to use a power amp for extremely needy headphones.
 
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