Mod your Beresford 7520

[HighFidelityGuy]

If I'm allowed to jump in Firefly is making an important point that class D or switching supplies operate at high frequencies, and need adequate filtering on the output to get rid of the noise and spikes that occur. Oversampling DACs also work at high frequencies and need filtering to remove the hash from the analogue outs. If the two are in the same case (or even if not) the layout and screening needs to work down beyond the microvolt level to make sure the one does not intermodulate the other and cause errors in the digital signal or noise spikes in the analogue signal. They are after all both micro radio transmitters

Thanks, I think I'm starting to understand.

So are you saying that using a switching power supply along with the Murata regulators (which have a high switching frequency) is likely to cause issues as the switching frequencies might interfere with each other?

[larry]

I recently got my Beresford TC-7520 DAC. I have burn in for about a week. I have been using it with Sennheiser HD 600 on the build in amplifier. My headphone also have about 100 hours burn in. I find the sound is slightly lacking in the low and mid part. I decided to change the two opamp to tweak it to my taste. What opamp is suitable for my problem?

[lingling1337]

I recently got my Beresford TC-7520 DAC. I have burn in for about a week. I have been using it with Sennheiser HD 600 on the build in amplifier. My headphone also have about 100 hours burn in. I find the sound is slightly lacking in the low and mid part. I decided to change the two opamp to tweak it to my taste. What opamp is suitable for my problem?

Since the HD600 is usually said to be amp-dependent, I'd choose a powerful amplifier like the THS4032CD. I ordered mine on Ebay from Tirna Electronics. Other users with high-impedance 'phones (K701 etc) report good results with the 4032.

EDIT: Of course, you would need to buy the version with the adapter. I assume you've read this whole thread, but if you haven't it's quite worthwhile.

[Gazjam]

Good post lingling

[larry]

Since the HD600 is usually said to be amp-dependent, I'd choose a powerful amplifier like the THS4032CD. I ordered mine on Ebay from Tirna Electronics. Other users with high-impedance 'phones (K701 etc) report good results with the 4032.

EDIT: Of course, you would need to buy the version with the adapter. I assume you've read this whole thread, but if you haven't it's quite worthwhile.

I have read part of this thread. This is a huge thread. So I change both to THS4032CD?

[StanleyB]

I mentioned it before, and I'll mention it again:
You guys should put a week or two (100 to 200 hours) or burn in on the DAC before deciding to try other opamps. One the DAC has been through the burn in the sound will be more dynamic and far rounded.
If you start swapping opamps too early, when the DAC has been a few weeks old the pronounced effect of an earlier opamp swap might result in you diving for an earlier opamp change.

I kniw of loads of people who have invested in various opamps, and ended up having several now lying unused on their desk.

The original opamp needs time to burn in. It has good bass and the tops develop over time. It has more bass than the LM4562 for a start.

Stan

[Covenant]

But it doesn't have that glorious midrange that the 4562 has. You know its good when you can almost read the fingerprints when a guitar is strummed!

Could op-amps be the new valves?

[StanleyB]

But it doesn't have that glorious midrange that the 4562 has. You know its good when you can almost read the fingerprints when a guitar is strummed!

Are you writing about line output or headphone output? And what is the spec of the mods that you are using to base your comments on?
I am getting increasingly worried that some people are refrring to mods on top of other mods. This clouds the original starting point reference.

I myself can hear enough detail in the guitar touches with the WM8716/LM4562NA combination, and which includes the MLC5/6 mod.
I get about the same result with the PCM1716/NE5532FE combination without the MLC5/6 mod. That's with the line output.

Things get a lot more complex with headphones. The 1st and 2nd opamp types can have a dramatic effect. I like the THS4032 in the LIne and the LM4562 in the headphone for the K701. For the HD650 I prefer the LM4562 in both location. My MDR-F1 is happier with LM4562NA in LINE and NE5532FE in headphone.

Stan

[Covenant]

Stan I am talking about the 4562 in line output (I dont bother with headphones), no other modification. I would have settled for this op-amp if I didnt experience the previously mentioned problems with bass which you describe as decay. Reluctantly I have replaced it with the 4032. This has (in my system) better control of the bass but some of the qualities of the 4562 have been lost. I have almost made up my mind to go back to the 4562 and try the MLC5/6 mod. I would like a couple more people to give some feedback first though.

[Gazjam]

Stan I am talking about the 4562 in line output (I dont bother with headphones), no other modification. I would have settled for this op-amp if I didnt experience the previously mentioned problems with bass which you describe as decay. Reluctantly I have replaced it with the 4032. This has (in my system) better control of the bass but some of the qualities of the 4562 have been lost. I have almost made up my mind to go back to the 4562 and try the MLC5/6 mod. I would like a couple more people to give some feedback first though.

JErry,
read my earlier comments.

Just one guys opinion I know, but I noticed a significant clearing away of the last layers of mush, particularly over the little things, like piano decay, fret noise, that kind of thing.

Music sounds more "alive" because of these wee things, and I thought the sound was a bit flat before with the 4562's.

Do the mod.
Just leave one of the Caps legs on so it can be easily soldered back on.

Me?
Im sticking with the 4562's, do all that I need..
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unless theres another super amp round the corner?
Now, just to find someone willing to "Wolfen" my 7520.......