Mod your Beresford 7520

Hi Zebu, welcome to the madhouse! :)

I know what you mean by the 4562 veiled quality - the vocals were especially well projected and real sounding, but sounded quite "flat" spacially to these ears.

LOVED the 4562 but swapped for the 4032 becasue of this.

They bettered the 4562 in a lot of ways, but I missed the "tingle" of the 4562s.

Then I heard about the ML5/6 mod.

Stan said it was recommended and it sounded like it fixed the problems I was hearing with the 4562.

I took the plunge and done the mod.

NOW THATS BETTER! :)

All the goodness from before but WITHOUT the veiled quality.
Only proviso I's say is that theres a little less deep bass than the 4032, but whats there is good and is secondary to the increased air and life about the music.

Id try the 4032 first though before you go snipping the Caps, it might be what your looking for.

Also, the DAC takes a long time (IMHO) to fully come on song - for me a good 6/8 weeks until it finally settled down to its best.

Best Regards,
G.

Hi ZebuTheOxen

Welcome to AoS - do the rest of us a favour and say hello in the entrance hall:)

I can't comment on the MCL5/6 thing as I have the TC-7510 (different beast), but the general consensus is that it is a worthwhile thing to do with the op-amps you have fitted.

The only suggestion I would make is play music through the thing for at least a week before you make any proper assessment of sound quality.

My TC-7510 took an age to settle down properly, both from new and each time I took a soldering iron to it (twice).

Enjoy your DAC and enjoy the forum - by and large we're a pretty good crew to get on with.

Chris:)

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Originally Posted by lingling1337

So aside from the opamp swapping, anyone have any bright ideas for bettering the analog output stage? The DAC swapping is all well and good to me, but really, the digital section isn't near as important as the analog portion.

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Apart from swapping the op-amps and snipping the ceramic caps out across the fb resistors to higher bandwidth theres not a huge amount to do in the analogue stage, maybe try alternative caps for coupling.

If you want to try something adventurous why not build an alternative output stage on vero board, solder on SIL pins so it fits in the existing socket, simply unplug the existing riser board and plug in the new one

Thanks for the replies, all very helpful! I'll introduce myself a little better tomorrow morning, it's been a long weekend.

I looked at the previous posts regarding the THS4032 and people describe it as 'dynamic' and 'forward', which I'm not sure if that's what I'm looking for. Just to give you an example, on Johnny Cash - Help Me before I would really feel the resonance of his guitar, the pluck of the strings etc. while it's still there (and more) it feels a little buried or something. I can only describe it as a veil for the lack of a better word. Maybe it could be the presence of proper bass is bringing something else to the table, this may account for the flattened sound.
The only reason I mention this is because when I first got the K701s, guitars really grabbed me. I know it can sound that good, I just want it all! :lol:

I mostly listen to rock, or 'anything with guitars in' so I would definitely say it is a sound that I actively seek out.

Though despite what I've just said, I have been flicking through tracks and the percussion / rhythm with the 4652s is absolutely fantastic. Drums crash rather than splash, plus all the other goodness that comes with it. Truly stuff to gird your loins with ;)

Stan mentioned the MCL5/6 mod to me specifically when I picked up the unit, if someone else can confirm what Gazjam is saying, it's very likely that it'll be the sound I'm looking for :)
Looking at Leo's post above, the capacitors are in the analogue part of the circuit, so it would make sense that removing a bit of filtering could open up the treble. Fingers crossed!

One of the nice things about this dac is that the output stage is simple, Apart from snipping out ML5/6 , fitting metal can LM4562HA for the line out I'm quite happy to leave the rest of the line out as is

I have a few pairs of headphones including K701's (a mate is currently borrowing them), I know these cans give a lot of amps a hard time to drive, they can sound a little lazy with light bass, sort of stick hitting a cardboard box effect ;) soon as I get them back I'll try a few different op-amps and see how it performs


Oh, welcome to AOS btw:)

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Originally Posted by Spod

good to see someone on this thread actually interested in 7520-modding rather than lingling-modding.

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Hah, that really tickled me for some reason.

Anyway, this MLC mod has me intrigued now. I might pick up a pair of 4562. How do those of you who have heard both compare the 4032 to the MLC modded 4562? Gaz?


EDIT: BTW, it would probably be helpful if we all specified what headphones we're using as that can really affect how we perceive different opamps etc. I'm on Grado SR225i.

Hi Zebu-(please explain your cattle based name). Thought I would add my two pennies worth. The 4562 has some lovely qualities especially in the mid-range. Acoustic guitar for example is a delight. Its about as close to being there as is possible. The reason I changed to the 4032 was because of a problem with excessive one note bass. I use floor standing speakers in a small room and consider the 4562 amplified the problem. The 4032 solves this for me but some may describe the sound as clinical or etched.
The ML5/6 mod plus 4562 may be an alternative but up to now I havent had the courage to try it.

I am surprised about the bass complaint made with the LM4562. It sounds far deeper and with more musical content to me and a few who tried it against the DAC1 (NE5532) and the DacMagic (NE5534).

The K701 has a dead low end on most headphone amps. So when you use it with the TC-7520 the enhanced bass can appear to 'sink' the midrange.
For K701 users and anyone who enjoys a wider bass range via headphones you can try the THS4032, or alternatively swap over the 47nF caps ( those big yellow ones on the top PCB either side of the headphone amp opamp, for a 100nF. I have instead soldered a 33nF cap in parallel with the 47nF from underneath the PCB so that I didn't need to desolder the 47nF. But that's for use with the K701. The added bass might sound a bit too much on the HD650 and other headphones that already have a fair amount of bass.

I added a modification page on my website at www.beresford.me that shows a number of the pictures taken by various AoS modders. I put some text with them as well. I hope to add and improve on that page over time. I hope it is helpful for a lot of people who don't know where to look for the various info.
Any useful suggestions on how to improve on that?

Stan

Have to say Stan that the website mod page for the 7520 is absolutely tops!

Are you planning a TC7510 one when you find a bit of spare time (what's that!).

Regards

Chris

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Originally Posted by chrism

Have to say Stan that the website mod page for the 7520 is absolutely tops!

Are you planning a TC7510 one when you find a bit of spare time (what's that!).

Regards

Chris

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I am looking for TC-7510 pics to post if anyone got any that I can have. Just email them to me at AoSPics@homehifi.co.uk. I'll worry about editing them etc.

I'll add some extra mods etc for the TC-7510. I just need to find where my TC-7510 with WM8716 is hiding. That mod needs two extra bits of wire links added, which is why I haven't made it available in general. I just can't remember where the links go either:doh:.

STan