I experienced the same problem. The 4032 give distortion in mainly the left channel of my headphone when placed in the headphone socket.:scratch:Quote:
Originally Posted by Dougr33
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I experienced the same problem. The 4032 give distortion in mainly the left channel of my headphone when placed in the headphone socket.:scratch:Quote:
Originally Posted by Dougr33
If the 4562 drives your headphones ok it maybe worth just having the 4032 in the fixed position only for now .
Phew ,
This thread has got so long its getting hard to find some specific info,
Is the same opamp shared for both headphone and fixed out duties?
And which one is it ?
True that! I searched back to where Stan said that the one over the volume control is the headphone, and the one over the headphone jack is the "output"... but he didn't say if both fixed and variable. But I noticed that if there's no opamp in the "output" socket, my variable output is much lower (yes, it makes music without anything at all... assuming that the DAC's analogue out has enough voltage to drive my amp).
You need a sticky;) keep all the tweaks and bits in
good idea Leo, if only i'd thought of it ages agoQuote:
Originally Posted by leo
Hmm, I assumed that the same op-amp was used for the fixed and line output and that the other op-amp was only for the headphone output. Perhaps that isn't the case. I guess it would make some sense that the headphone op-amp was also used for the variable output as both of these use the volume pot.
Perhaps this means that the variable output also has a different impedance or something than the fixed output, which would maybe explain why they both have different characteristics.
I guess we need some clarification on this from Stan.
http://theartofsound.net/forum/showt...?t=2160&page=6Quote:
Originally Posted by HighFidelityGuy
Posts 55 and 56.
"ones for the fixed and the others for the 'phones?" Answer::) (from those posts)
Doesn't really answer the question. When I took the op amp out of the 'fixed' socket, the volume (of my variable output to my power amp) went way down. I think the phones and variable out are different chips. Would love to know.
What volume?Quote:
Originally Posted by Dougr33
repaired my post above... the volume of the variable output to my directly connected power amp was much lower with no opamp in the socket, so I "think" it's not the same as the headphone opamp. But I really don't know crap about this!Quote:
Originally Posted by trailer
Neither am I to be honest(!). But I'm sure I remember seeing that the two chips should be "variable (ie variable line out AND headphone)" and "fixed (fixed line out)".
Over to Stan!
Who has two 4032s installed, and can you listen to your headphones at lower volume without obvious noise/distortion??
I have two 4032's installed and everything sounds fine through the headphones. No crackles or distortions. I can't turn the volume up very high but I have got quite low impedance phones (32 ohm I think), so that's what you'd expect, I think.
It's only when I connect my power amps directly to the variable output that odd things happen.
which is how I use mine. Well, we'll see who else replies. Maybe it's only when using the variable out (the whole reason I went this route). Well, I'm less a headphone listener, so the 4562 on that socket (if indeed it's separate from the variable) would be fine... but it would show, to me at least, that it'd be nice if Tirna had tried their "upgrade to Beresford 7520" on a actual Beresford 7520.Quote:
Originally Posted by HighFidelityGuy
When I emailed Stan directly about the two opamps he indicated that the variable out (preamp) and line out use the same opamp.
It might aid you folks understanding to remember that these are DUAL op-amps :)
and also stop some people blowing up their TC-7520. On at least two cases the pins on the modded PCB from them has shorted against the top case of the DAC. At least one perosn has also put the modded PCB in the wrong way round.Quote:
Originally Posted by Dougr33
Those DAC were then history.
I am NOT recommending the Tirna modded PCB as a result of those blown up DACs. Neither am I offering any technical advise or encouragement to those who are prepared to risk blowing their DAC up that way.
I recall a posting somewhere from Stan where he said he changed a few resistors around the opamp board. Maybe this is related to the distortion some are getting.Quote:
Originally Posted by Dougr33
re some of the other comments/requests:
We can't expect Stan to spend time on advising, he's in business to sell the DACs he developed. Given the low cost of the 4032 chip and board we can't really expect Tirna to source a 7520 to test the upgrade either. They are simply responding to a specific market demand which makes them a little money but I very much doubt it would justify say 10 hours work on testing and guarantees for the upgrade.
Well put.Quote:
Originally Posted by Clive
Ok, so both line outputs use the op-amp on the left. Thanks. :)Quote:
Originally Posted by ReachtheSky
As far as I understand it; one channel of the op-amp is for the left channel, the other for the right, giving you stereo. :)Quote:
Originally Posted by technobear
I'm going to do some testing tonight with a scope on the line outputs with different combinations of op-amps to try and narrow down the cause of my problems.
Would you fit a replacement part in your car if the part manufacturer has not tested it on the car in question?Quote:
Originally Posted by Clive
Depends on the part Stan. Something seriously mechanically internal or electronics that interact with the CAN-bus I would want testing. Whereas a wheel or tyre of suitable spec should be interchangeable without testing.Quote:
Originally Posted by Sensimilia
Opamps are closer to the wheel & tyre analogy although there are risks that they aren't 100% suitable for the parameters you set for the 5532. It's a small risk though that's unlikely to result in damage, excepting errors in doing the opamp install.
You should see my email inbox:doh:. Homer lives...Quote:
Originally Posted by Clive
Okay, hope not to offend, but:Quote:
Originally Posted by Sensimilia
1. agree with Stan on this, but because the exact title of the Tirna ebay item was "THS4032CD Dual Op Amp Beresford DAC Upgrade 8 PIN DIL "
I strongly feel that if you're selling an "Upgrade" to anything, you should have tested it in the box. I'm not very happy that I was sent two that didn't fit the case, and now two that can only be used one at a time
2. No offense Stanley, but I think you're being a little coy about this. You're the one who told us this was your Favorite Opamp, and gosh, aren't we lucky Opamps are so easy to swap in your box. How about a little help on how to implement the 4032. Why would it do what it's doing in my box?
Thanks!
Looking back through previous posts should make it clear that the THS4032 is a very capable op-amp WHEN IT IS IMPLEMENTED CORRECTLY. It is a very high speed device which requires some care where it is fitted. The stock NE5532 on the other hand is much less fussy, being a very slow (relatively) chip. Heaving out one device and sticking in another is therefore prone to bringing up problems, as things like length of pcb track can cause instability.Quote:
Originally Posted by Dougr33
The 7520 HA board has been designed around the 5532 NOT the 4032, so a certain risk must be involved in this kind of upgrade.
The THS4032 is a very fine sounding chip, but not wanting to start swapping out other components to make it stable, I personally will stick with an op-amp I know sounds (almost) as good - ie. the LM4562.
Ken
My own favorite is the opa2132pa.
Got the revised mod from Tirna and was disappointed. Still too much height and would not fit in my dac properly.
I have nothing against the THS4032. My concern is with the PCB adapter, which is blowing up people's DAC at worst, or only the fuse if they are lucky!Quote:
Originally Posted by Dougr33
The only sure fire way to fit the mod is to desolder the DIL adapter socket I fitted for the NE5532, and then solder in the SOIC to DIL adapter PCB with the THS4032 on it. Anyone in the UK who can't do that part of the job but would like it done should email me for the details of a fellow engineer who has offered to do the mod for them. The top PCB is removable, so that's all he'll need.
Well, maybe I misunderstood.. I assumed that if you thought the 4032 was best, it was a drop in for the socket you provided (to making opamp 'rolling' easier). I'd like to see if anyone is having issues with 2 Tirnas in the board. I'm not against the 4562 in for the HPA, and not even sure if I like the 4032 better in the variable out. But I'm not quite up for soldering if not certain the 4032s better all around..
I'm curious...what's the effect of the pin 4/8 decoupling cap still on your board in combo with the one Tirna puts on (because the board cap would be too far away due to pin/adaptor/adaptor length)?
Now I understand your concern. I take back my comment about low risk. I have 4032 from Tirna ready to install. Time to get my IC desoldering tool out to desolder the IC socket.Quote:
Originally Posted by Sensimilia
Did a lot of people just buy one??
I did. I really like the way my AKG K701 sound with the LM4562NA. But the THS4032CD on the output is something to be heard. This DAC has never sounded that good since I purchased it. All in all, this combination works great with my rig. YMMV. :)Quote:
Originally Posted by Dougr33
It would be great if Stan or anyone else with more knowledge could advise if there is likely to be any long term damage caused by the Tirna 4032 mod assuming that there is no obvious initial problem.
In my case I just have the 4032 on the left hand socket and a 4562 in the headphone socket. The quality is perfect and I would be reluctant to change unless problems are going to develop.
Just by way of a change from op-amp related issues - What power supply units are you guys using to power your TC-7520?
I ask because I have an idea to use a single 12volt/5volt dual SMPS to power both my DAC and Squeezebox Classic. At the moment I am using a homebrewed 12volt linear for the 7520 and the stock 5volt switcher for the SB3.
My reasons are: 1. Convenience - Just one mains socket. 2. Lower power, more efficient. 3. Better performance than the stock wall-warts.
What have I got to lose? Will the sound quality suffer?
Any comments ...
Ken
I'm using the Maplin recommended PSU with an after Market kettle lead. Noticably better than the supplied wall wart
Same here. Maplin PSU at 12v.
You tried at 13.5V?Quote:
Originally Posted by trailer
Any thoughts?
I did with the 7510. Found it too lively and forward. To be honest I haven't tried the 7520 at 13.5v. Have you?Quote:
Originally Posted by Gazjam
Are these Maplin PSU's linears? - Do they do a 5volt unit at about 2 amps?
This one:Quote:
Originally Posted by sponge
http://www.maplin.co.uk/Module.aspx?ModuleNo=48517
OK, thanks for that. Is there a worthwhile improvement over the standard wall-wart? I know there is with my 12V linear, so I wouldn't like to lose that improvement.
I haven't tried the 7520 wall wart. I just plugged the Maplin in straight away as it did make a small improvement to the 7510 so I assumed it would with the 7520.
I found the same thing with my 7510.Quote:
Originally Posted by trailer
It was like pressing the "Loudness" button in my system - too much of everything.
No haven't even thought of trying 13.5v in mine.
Will do tonight and post back.
You should too when you get a chance? Might be useful info?
Gaz.
Have you guys had a meter on the PSU output? Is it pretty close to the stated voltage? I am running my linear PSU at 12.5V (measured) as this was similar to the wall-wart's output.
Ken
Won't running the DAC at 13.5V lead to risk of burning out or damaging something if used long-term?
(I only ask 'cos I'm quite liking the description of the "problems" being listed with the sound at 13.5, sounds temptingly intriguing - sometimes I like the music shouting in my face!)
The spec is 12V to 15V, there are internal regulators. Also the PSU will likely sag a little under load. So if you measure 14V off-load, it's likely to be 13.5V on-load.Quote:
Originally Posted by Spod
Anyone tried one of these?
http://uk.farnell.com/texas-instrume...dip/dp/1648692
I would but it's away getting Wolfson'ed :cool:Quote:
Originally Posted by Gazjam
Whos it away with?Quote:
Originally Posted by trailer
Just suppose you don't like it - Do you then get it Burr-Browned :scratch:Quote:
Originally Posted by trailer