Mod your Beresford 7520

[Stratmangler]

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

Just cut one leg and lift the cap away without removing it. If you want to put the cap back in circuit then a blob of solder on the cut should suffice.

Not ideal, but a damned sight easier than removing the circuit board and desoldering the joint, replacing the cap etc.

Chris

[Dougr33]

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?

Maybe the metal version won't react as well with the cap mod??? Seems hard to guess these things. But on behalf of the rest of us, give it a go!! (and thanks!)

[Gazjam]

Will do.

The metal caps a fair bit more expensive which hopefully suggest something better.


HAd a search thru the thread, not many references to the differences between 4562 std and the metal cap one.

[StanleyB]

The metal version works fine with the cap mod.

My take on the reason why the THS4032 is so temperamental is because it is a surface mount device and just hates being in a socket. Those adapter pins might be acting as aerials at high RF. Maybe the THS4032 requires desoldering of the existing socket and then solder the THS4032 on its adapter board directly onto the top PCB.
If anyone has a pair of THS4032 and adapter boards to spare I can experiment and publish my findings. I have used up my samples on a different project.

Stan

[Gazjam]

I've one of the Tirna 4032's lying spare, any use Stan?

[leo]

For me at least I'd definitely say metal can LM4562HA is a better performer than the plastic dip8 NA version
Its not a huge difference and tbh I cannot say everybody would agree the increase in performance is worth the extra expense, best way of describing it is that theres a bit more there with the HA, sounds a bit more polished
Only reason I can think of what causes this is if the thermal matching internally is better with the metal can, maybe its also slighter tighter on the specs

Removing those 100pf ceramics is a real must with the LM4562NA or HA op-amp (and works great with a few other types of op-amp too)

With the caps removed the THS4032 didn't burst into immediate oscillation (for me anyway) it was with higher frequencies (16k+) with the caps removed which made it slightly touchy , LM4562 gave a solid sinewave , THS4032 would behave from cold and go into occasional ringing after a minute or two higher up the range but not bad
I can't measure music but it would probably behave with normal signals?
Also thing to note is that having the ceramic cap DIRECTLY onto the THS4032 pins (not its socket pins) does help
I think without the socket found on the 7520 riser board may prevent any ringing at all


Anyway, heres a few signals with those caps removed
Also note I have WM8716 fitted

1k Square wave 0db LM4562 minus MLC5/6, pre and post ringing is usual, it varies depending on the type of OS chip used



1k Square wave 0db THS4032 minus MLC5/6



16HZ Sinewave 0db LM4562



50HZ Sine wave 0db LM4562



500HZ Sine wave 0db LM4562



2K Sine wave 0db LM4562



20k Sine wave 0db LM4562

[StanleyB]

I've one of the Tirna 4032's lying spare, any use Stan?

Of course it would. Just send it over.
If anyone else has one more to donate in kind, let me know. I could even test them in the Caiman.

Stan

[StanleyB]

It's interesting to note the DAC's performance at 16Hz Leo. I wonder how many other DACs have such an even response below 50Hz. The waveform measurement goes to at least debunk any claims of lack of LF bass. No drop off to be seen there.

Stan

[leo]

It's interesting to note the DAC's performance at 16Hz Leo. I wonder how many other DACs have such an even response below 50Hz. The waveform measurement goes to at least debunk any claims of lack of LF bass. No drop off to be seen there.

Stan

Not bad eh

I've had a few dacs here which give nice spirograph effects higher than 16k 7520 using WM8716 remains spot on!

Cameras fault for not showing full 16hz, you can see though no rolling off at all

[ZebuTheOxen]

Please don't start talking about the WM8716, I'm already way too tempted to fiddle with the components as it is.