Mod your Beresford 7520

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12-07-2010, 03:57
fmzip

Quote:

Originally Posted by AndrewR

I've tried the LM 826, but still far preferred the OPA2132PA.

Much better still is removing the board and fitting 47uF capacitors into the PIN3B connector - as per post 117 in the passive Caiman thread

Andrew

Gotta say, this is nice! Thanks for the link!

Guess I have now determined my op amp board was the problem with the lost channel I was struggling with....

I have music back and it is sweet. Time to let the Nichicon Muse caps burn in for a week or two :)
13-07-2010, 19:06
Maximum

I'm testing out the metal cap version of the LM4562 and results initially are quite positive. They are bloody awkward to fit though and clearance looks like it'll be a problem. Does anyone know any potential problems with the dip adapted ones like the ones sold here...

http://www.audioupgrades.co.uk/na_ma_ha_opamps.shtml
22-08-2010, 10:14
RoboCopper

Quote:

Originally Posted by Quietschbox

Well, i don't know... browsing pages along the 4032 and 4562...

"Ad8620 Vs. THS4032"
http://www.diyaudio.com/forums/showt...postid=1658008

"In my Twistedpear COD DAC, at the balance to single conversion position after the AD826 IV, I have tried both AD8620 and THS4032, also LM4562, AD8066, LM6172, OPA2132 and OPA2064 etc.
*For pop/jazz/vocal music, I prefer THS4032 - a lot.*
The difference between THS4032 and other amp in this case is day and night. It sounds a lot fuller, more importantly, it has much better pace than other amp. It is simply more musical. It tips towards the lower end. But that is what I am looking for. Comparing to the Twistedpear Buffalo, the COD in on the thin side.
You have to try out THS4032."

Something for you?

This thread also says:
http://www.diyaudio.com/forums/showt...01#post1156001
"Have you checked the data sheet for the THS4032 compared to the older NJM4580?
It says the OP-amp (THS4032) cant drive a capacitive load unless it is smaller than 20pF. Check all outputs (pin 1 and pin7) to see if there is a proper protection resistor for to avoid oscillations and unstable operations. If there is capacitors connected right on the outputs it could be necessary to apply a series resistor from the output (20-75 ohm maximum). But Im not sure about the solution due to I dont have any schematics for the SRC2496 to look at and you havnt verified the oscillation on a scope?
Due to the high bandwith, this circuit operates in class-A and because of that it will be running pretty hot (ca 0.5W heat dissipating for each IC) but could of course run to hot if oscillate."

and

http://www.diyaudio.com/forums/showt...28#post1156028
"Oscillating op-amps distort the sound badly, and that's what you are enjoying and calling "SOOO OOOOOPEN", distorted sound. Most pre-amp mods are actually based in making some stage oscillate by accident, but don't say it too loud or some people may become upset... (Anyway, the kind of people that does this stuff neither have an oscilloscope to check nor care about stability at all)."

and

http://www.diyaudio.com/forums/showt...38#post1156238
"You can't use the THS4032 for most audio applications because IT'S NOT UNITY-GAIN STABLE, and most audio circuits require that condition. This op-amp is only stable for gains of 2 or higher, as it's intended for video buffering applications. There is no simple way to make it unity-gain stable.

Also, you can't use the THS4032 with +/-15V in a PCB designed for conventional op-amps because it requires specific layout considerations in order to handle those 0.45W of idle dissipation. Furthermore, most PCB layouts designed for conventional audio op-amps just can't handle the 100Mhz bandwidth."

and

"first thing you should do if wanting to mod circuits should be to purchase a decent oscilloscope for a couple of bucks. Analog instrument are nearly for free now a days and that will be your first choice measuring instrument to use if your intention is to modify circuits. Also, you will learn a lot when using such an instrument and also, its very very useful for all electronic developments, error measurements, modifications and services on broken/faulty equipments.
Otherwise all your future works with modifications will newer be verified only estimated by a guessing.
It will do with a scope in the range of 50 to 100 MHz, (best=100MHz) but you dont need a 2 channel scope, but its very convenient to be able to see what is coming in and what is coming out at the same time when measuring."

Not that i understand enough of it, but warnings about how to implement this thing, would like to get the hang of whats that all about...

http://www.diyaudio.com/forums/showt...35#post1659635
"I got THS4032 and THS4031.
they sounds good.
extended highs , full mids , well controlled and punchy lows.
The only thing I am not satisfied with is that sound stage is a bit narrow compared with traditional Audio OPAMP."

So many opinions on things. I once decided electronics is too much mathematics for me, so i stopped at basic level. Every once and then,
things like these make me wish i knew more and had some gear.

After reading this post, I wonder if THS4032 is compatible with Beresford 7520 DAC?
Would someone suggest it?
Any sound reviews if it is safe to use?
If it is compatible and good to use is this a good price?
http://cgi.ebay.co.uk/ws/eBayISAPI.d...m=360292194570
29-08-2010, 18:24
RoboCopper

Quote:

Originally Posted by StanleyB

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

Stan,
I am only listening to line output and at present time I have 7520 with LM4562 with MLC5/6 mods.
Would you also suggest PCM1716 to WM8716 upgrade as I have a friend who knows better his soldering iron than I do know my pocket :)
What is the difference in sound when PCM1716 is upgraded to WM8716?
Anybody, any experiences?
Best regards
02-09-2010, 13:03
TeTsuo36

Just realised i had not been here and posted for over a year! That is what a baby, another baby on the way and a loft conversion does for you.

So my 7520. WM8716 Wolfson, 4562NA on the headphones and THS4032 (with cap) on the line out. No other mods.

I wanted to do the MCL 5/6 mod, but figured i may need to change the THS4032. I ordered a 4562NA and some of the LMEs. I wanted 4562HA, but National don't appear to do samples and at Farnell they are £20. Anyone have a cheaper source? Would i even notice the difference to the NA?

Also, may i ask. How do you fit a 4562HA? With the adaptor or soldered straight in to the pcb?

Thanks in advance, great to see the mods still continuing, looks like i have a LOT to catch up on.

All the best, Mark.
02-09-2010, 14:12
AndrewR

Quote:

Originally Posted by TeTsuo36

Just realised i had not been here and posted for over a year! That is what a baby, another baby on the way and a loft conversion does for you.

So my 7520. WM8716 Wolfson, 4562NA on the headphones and THS4032 (with cap) on the line out. No other mods.

I wanted to do the MCL 5/6 mod, but figured i may need to change the THS4032. I ordered a 4562NA and some of the LMEs. I wanted 4562HA, but National don't appear to do samples and at Farnell they are £20. Anyone have a cheaper source? Would i even notice the difference to the NA?

Also, may i ask. How do you fit a 4562HA? With the adaptor or soldered straight in to the pcb?

Thanks in advance, great to see the mods still continuing, looks like i have a LOT to catch up on.

All the best, Mark.

Tetsuo,

Two words - "Passive Mod"

Four words - "Got to be done"

See my post #117 in the passive Caiman thread.

Enjoy!

Andrew Randle
02-09-2010, 14:30
Alex_UK

Quote:

Originally Posted by AndrewR

Tetsuo,

Two words - "Passive Mod"

Four words - "Got to be done"

See my post #117 in the passive Caiman thread.

Enjoy!

Andrew Randle

Here's the link, to save other people searching.

http://theartofsound.net/forum/showp...&postcount=117

Sorry if this has been stated, but I'm not clear - does this leave the headphone/variable output still working? [Ignore this question - just re-read - No and Yes as far as I can tell.]
02-09-2010, 14:53
lovejoy

Quote:

Originally Posted by RoboCopper

Stan,
I am only listening to line output and at present time I have 7520 with LM4562 with MLC5/6 mods.
Would you also suggest PCM1716 to WM8716 upgrade as I have a friend who knows better his soldering iron than I do know my pocket :)
What is the difference in sound when PCM1716 is upgraded to WM8716?
Anybody, any experiences?
Best regards

Oh yes, do it, without a doubt. The differences to my ears are in the frequency extremes when you swap out the PCM1716 for the WM8716 - deeper, more tuneful and better controlled bass and cleaner, sweeter and easier to listen to top end. If you know someone who can do the job for you, it's a no brainer.
02-09-2010, 22:15
TeTsuo36

Quote:

Originally Posted by Alex_UK

Here's the link, to save other people searching.

http://theartofsound.net/forum/showp...&postcount=117

Sorry if this has been stated, but I'm not clear - does this leave the headphone/variable output still working? [Ignore this question - just re-read - No and Yes as far as I can tell.]

Thanks, looks like whole new thread to get into. Passive mod is easy enough but does it only mod the fixed channel? My amp has no volume (diy Tripath TA2020) damn..........
26-09-2010, 19:02
donington

Hi, all im new here and could do with some help, i want to put the cl5/cl6 resistors in the beresford 7520 back in to see if it would help to rein in the harsh top end,i did the lm4562 mod which was a huge improvment but after over 2 months of use still had the same problem then i put the an826anz in which again was a worth while change but i still get some harsh treble but not as bad,what i need help with is getting the right resistors and were from.I want to try this before i change my speakers which i think could help they are the monitor audio br2 and with there metal tweeters might not be helping im a novice so please be gentle any help would be great regards keith:)

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