Mod your Beresford 7520

Quote:

---

Originally Posted by leo

Looking good, it just needs the text 100nf changing to 100pf for MLC5 & MLC6

Also I think some noted problems if using THS4032 in both line out and HA positions where as it was ok if used in one side only

---

I was one who had this issue. With two 4032s, the HPA was distorted (and crackly?... can't remember, as it was two months ago and I took it out right away). So I went with 4032 on line out, 4562 on HPA.
Wanted to add that someone reported no problem with 2, and so I note that my Sennheiser 595s are only 50 Ohms, and that might be the culprit.

Am I seeing that the preference for line out is now back to 4562 with the caps cut instead of the 4032s. I've been happy, but I could switch and cut!!

Have you tried the 4562 in the line out circuit Doug? Just try swapping to see if you like what it does. You can always do the ML5/6 mod at a later date once you have established that it works for you.

I went ahead and ordered a 4032. Wasn't sure about getting 1 or 2, but the gent on the previous page had a bad experience with 2 x 4032.

Hopefully it'll bring out what I know the amp is capable of :)

Stan,

I'm just wondering if the caiman psu will become the standard psu for the 7520 or will it become an extra option that will cost more money.

Hmm sorry for my noobyness here, i just read up on the new/upgraded 7520 power supply thread and it seems like you commented that due to the 7520 design the psu would not make a change to the sound but it seems like you also give the impression that caiman psu did improve the 7520. I'm a bit confused now.

Quote:

---

Originally Posted by Covenant

Have you tried the 4562 in the line out circuit Doug? Just try swapping to see if you like what it does. You can always do the ML5/6 mod at a later date once you have established that it works for you.

---

Yep...started with two 4562s as my first mod(big improvement over stock opamps). Then (I thought) folks felt the 4032 better.. and indeed I preferred it a bit over the 4562 in the line out (and had the mentioned trouble with two of them.)

Noticing that now some say 4562 PLUS cut caps is better, but not sure I want to mess.

Can anyone direct me to a post describing the improvements seen with the Caiman mods. I'm considering getting it. Thanks!!

Quote:

---

Originally Posted by sum1

Stan,

I'm just wondering if the caiman psu will become the standard psu for the 7520 or will it become an extra option that will cost more money.

Hmm sorry for my noobyness here, i just read up on the new/upgraded 7520 power supply thread and it seems like you commented that due to the 7520 design the psu would not make a change to the sound but it seems like you also give the impression that caiman psu did improve the 7520. I'm a bit confused now.

---

The Caiman PSU appears to offer a change of sound with the standard TC-7520 on the systems we have tested it on. However, it is not a uniform decision amongst my beta testers if it is a good or bad change. So I am not sure at this moment if I would recommend the Caiman PSU to every standard TC-7520 user. I would have to conduct some wider trials to get a more meaningful consensus.

What we have noticed that is more encouraging is that it offers a pleasant change with the LM4562/MLC5/MLC6 mods. However, it does not look so good on the scope with the THS4032 as far as stability of the signal is concerned. Maybe Leo might be able to offer us some insight in this.

Since these tests and trials are work in progress, I wouldn't say that you should take anything for granted. Once I can conduct a bigger trail when I have some legally approved samples of the PSU to send out there would be more hard and concrete technical information available from those running the trails. Depending on the results, I might offer a mod option for the technically challenged whereby those people send me their TC-7520 and I do the opamp and caps mods and include the Caiman PSU when returning the DAC to them. Again, this is just an idea. The Caiman PSU is not yet ready for production. There are delays being experienced. It is awaiting CE and VDU approval before the factory can even book me a slot to do a limited production run.

What should be realized is that I am trying to create improvements with a PSU design costing less than £30, when similar improvements can only be accomplished by other DAC and headphone manufacturers with their PSU costing £100 and upwards. So bear with me. It ain't easy to create a DAC/PSU combination for less than £300 that can hold its own against £10K CD players and £3K DACs.
That remnds me that I need a few more beta testers who have CD players costing at least £2K or DACs costing at least £1K who would be willing to do some testing against their set up if and when I need their help.

Stan

Quote:

---

Originally Posted by Dougr33

Yep...started with two 4562s as my first mod(big improvement over stock opamps). Then (I thought) folks felt the 4032 better.. and indeed I preferred it a bit over the 4562 in the line out (and had the mentioned trouble with two of them.)

Noticing that now some say 4562 PLUS cut caps is better, but not sure I want to mess.

Can anyone direct me to a post describing the improvements seen with the Caiman mods. I'm considering getting it. Thanks!!

---

An intersting observation, now I've had the ML5/6 mod done for some time now...

the sounds changing.

Theres a "hear through" clarity I didn't have before. Straight after doing the mod (last week) there was an immediate imporovement with a better sense of "air" around instruments and everything sounded more alive, but from last night the sense of space front to back has increased very noticably. The soundstage too seems to hang together better as a whole, not a collection of individual elements (if that makes sense?)

The more cohesive soundstage was the advantage I found the 4032 to have over the 4652 but as I said before, the 4032 lacked the "spark" the 4562 had.

Oh, and the issue of lacking bass?
Not at all.
Its all there but through the 4562/ML5,6 mod its very much tighter.
If its not sub bass it wont sound like it.

I think its a product of the Dac having such high resolution and clarity now - a layer of mush has been stripped away.

Played Dark Side of the Moon and theres a deep pulsing bass at the start and if anything, the bass was DEEPER than before. I was getting thumped in the chest in a way I wasn't before.

To these ears this is the best Opamp setup I've heard and the best my systems ever sounded.

Ahhhh I can't handle the suspense any longer. I was going to wait a while before I tried the 4562+MLC5/6 mod as I'm happy with the 4032 but after Gazjam's last post I've got to try this sooner. I'll be using the metal can 4562 though. I'll hopefully try this tonight.

Oops. Sorry! :)

The metal can one is supposed to be even better, think thats my next step.
Wonder how much of an improvement there is over the standard one...Leo?

How would one go about repairing the capacitor legs once cut?