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Old 14th July 2011, 05:05 PM   #181
wlowes is offline wlowes  Canada
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Andrew,
I look forward to your results. The description you post is what I should have written about the effect of the 200pf cap!! If he is seeing yet another jump, that's quite alot. I hate to be dramatic, but in my case based on 45mins sample I would class it as a different machine. Results were not small.

good luck with your work.
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Old 14th July 2011, 05:31 PM   #182
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Quote:
Originally Posted by SimontY View Post
I like the idea of the 1541 losing a bit of excess colouration as I do find it emphasises the upper bass and lower mids a bit too much.
. No; I'm damn sure what you are hearing is the effect of (your) implementation of regulators... and supply decoupling. These have a simply massive effect on the TDA1541 sound quality (and the SAA720 for other reasons).

Yes there are lots of other tricks too but making good regs really work is worth the effort over just replacing the 7805 or whatever it originally had like-for-like. Kick-*** dynamics, for one thing...
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Old 14th July 2011, 07:38 PM   #183
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Hmm, I'm a little sceptical. I doubt I'm missing that much with my almost direct and dedicated super-regs. I think you've also not seen how my machine is modified. I've not replaced many regs, most are added in new locations... though the DAC board regs are, admittedly, in the same locations as stock.

Simon
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Old 15th July 2011, 12:58 AM   #184
wlowes is offline wlowes  Canada
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Quote:
Originally Posted by SimontY View Post
I like the idea of the 1541 losing a bit of excess colouration as I do find it emphasises the upper bass and lower mids a bit
Simon
I had the same impression. I was very happy with it, but there was a bit of an emphasis as you state. I have not measured my speakers, but they are likely a bit bright. As I kept getting more clarity thru changes to the arcam and to my linestage, I was beginning to think I needed to work on my speakers as the sound was becoming too edgy in the upper registers. The vocal hiss had a harsh edge on some recordings. Words like this or kiss had a sizzle at the end. Following the reclocking, this has disappeared. I'll comment more after I thoroughly listen to this 'new' machine.

Real is the new impression. Loads of micro information in the background. I ran a few samples of classical and opera. My system was doing great on Jazz and blues, but it was not really up to classical. A little muddled. I figured that I'd need to defer that to when I get around to addressing the speakers or even the amp. Not so. This stuff just jumped to life.

My main project is long a long slow run at building my first tube amp. I think getting the source really right will be important before this comes online. Its clear that my current amp is not the limitation, it remains the source.

Here's a preview of the amp project, btw - just finalizing the layout. Very exciting..
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Old 15th July 2011, 01:23 AM   #185
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Oh yeah - loving that pic !!
Want one of those

It did not work guys - sorry
Distortion - no music.
I think I know where the problem lies and will try the fix in the morning

Too tired of looking at it - NO smoke, burns or shorts - all is well

8 hours is too much

Night
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Old 15th July 2011, 01:25 AM   #186
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OK, exaggeration - 8 hours is not true

Make that.. 10

So f.....g p.....d off
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Old 15th July 2011, 07:22 AM   #187
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Originally Posted by SimontY View Post
Hmm, I'm a little sceptical. I doubt I'm missing that much with my almost direct and dedicated super-regs. I think you've also not seen how my machine is modified. I've not replaced many regs, most are added in new locations... though the DAC board regs are, admittedly, in the same locations as stock.

Simon
... and supply decoupling. These have a simply massive effect on the TDA1541 sound quality (and the SAA720 for other reasons).

I was sceptical about the audible effect of regulators & supply decoupling caps mods.
I have been messing with an old Philips CD471 (tda1541)-trying I/V transformers, LC filters etc whilst awaiting the arrival of a dual differential 1541a based kit.

So I chopped off the 30year old supply decoupling caps and soldered Oscons direct to the IC pins (just the 5volts ones - couldn't get at the -15v pin).
I was pleasantly surprised how audible the result was. Its hard to put it into words - everything was a bit clearer, sharper, more focussed and bass tighter. A bit like a veil has been lifted off the speakers.
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Old 15th July 2011, 09:32 AM   #188
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Exactly, its the very detail of the implementation that matters - often more than the parts. Another example, a reg's performance is limited where it is is sampling the supplied voltage. If that is 10cm away from the load device, across thin tracks sharing noisy currents with other circuits, then its benefit is often degraded badly. It's always worth a good think about how 'good' drop-in 3pin reg replacements can perform from this POV.

Related to this - a good reg similarly remote from the circuit it serves but with a high-quality output cap onboard might have made the HF 'current loops enormous and noisy - because the local decoupling cap is old/dried out/not very good at RF and so on. Decoupling should be as tight as (and as good as) you can arrange, right at the load, not the reg!

These are the things I was getting at before I lost the original post I was going to stick up last night!

Last edited by martin clark; 15th July 2011 at 09:34 AM.
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Old 15th July 2011, 09:43 AM   #189
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Andrew, that really sucks. What's the problem?

batteryman,

Good to hear your experiences. I'm using os-con SEPCs on the -5 and +5V DAC supplies. I find such changes are audible but nothing like the BIG veils that come off with good regulation and dedicated power supplies. You will like that if you've not gone there yet. I found the smoothing caps on the DAC supplies to be really crucial too!
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Old 15th July 2011, 09:59 AM   #190
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Originally Posted by SimontY View Post
Andrew, that really sucks. What's the problem?

batteryman,

Good to hear your experiences. I'm using os-con SEPCs on the -5 and +5V DAC supplies. I find such changes are audible but nothing like the BIG veils that come off with good regulation and dedicated power supplies. You will like that if you've not gone there yet. I found the smoothing caps on the DAC supplies to be really crucial too!
The Dac kit from rainbow_hui on ebay appears to feature discrete regulators (haven't received it yet) so here's hoping they sound better than IC regulators. I'll be upgrading some of the caps as well,not to mention converting it to dual differential and listening out for the benefits of dem reclocking and i2s attenuation.
BM
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