The discrete TC-7520(SE)(+) line output

[StanleyB]

The opamp is only needed for the headphone stage. If you don't use headphones then the choice of opamp is only important for the correct operation of the PCB.

[Kendalbeefcake]

Hi,

After a massive palaver with headphones, I finally got to fit the Gator and listen to it..And I've got a problem.

I'm only listening to headphones but there is a lot of noise/crackle coming through. It's weird because it's not constant and only on some frequencies (such as the same word twice in Adele's "home town"). Some tracks it only comes through a 3rd of the way through, or not at all..

I'm listening to FLACs from my Music server via coax. I still have the stock PSU, and otherwise I'm totally unmodified..

I was literally about to send it off to Tirna for the Caps and other upgrades, but I can't really send it like this..

"You know I'm no Good" by Amy Winehouse does it as soon as she starts to sing, but the next tracks "Mr and Mr Jones" and "Just Friends" don't do it at all (I've just gone back and played them again, same result). It also does it if go anywhere near the volume control..

Forgive me if I've missed anything obvious, but I did follow the instructions..

What have I done wrong?

Edit: I'm using the Stan supplied & fitted AD826 rather than stock op-amps..

[Paul]

The opamp is only needed for the headphone stage. If you don't use headphones then the choice of opamp is only important for the correct operation of the PCB.

Thanks for clearing that up Stan .

[StanleyB]

Hi,

After a massive palaver with headphones, I finally got to fit the Gator and listen to it..And I've got a problem.

I'm only listening to headphones but there is a lot of noise/crackle coming through. It's weird because it's not constant and only on some frequencies (such as the same word twice in Adele's "home town"). Some tracks it only comes through a 3rd of the way through, or not at all..

The pins on the original PCB have widened the socket clamps in the connectors on either side of the headphone socket. You can lift the black covers off those connectors on the bottom board and CAREFULLY bend the clamps a minuscule bit inwards. That will restore proper contact between the pins on the Gator and the clamps underneath, and get rid of the intermittent noise.

If that's a bit scary, send the board back to me and I'll coat the pins with a slight dab of solder, which will sort out the crackle. Even if you have a soldering iron, don't attempt tinning the pins yourself unless you are very skilled. Tinning those pins is not as easy as it seems. A bit too much solder, and the pins won't go into the socket underneath..

If you need pictures on the first suggestion, let me know and I'll drag myself out of my sick bed to the workshop. Yep, I got a bad flu for weeks now, but luckily my staff are taking care of business for me.

[Kendalbeefcake]

The pins on the original PCB have widened the socket clamps in the connectors on either side of the headphone socket. You can lift the black covers off those connectors on the bottom board and CAREFULLY bend the clamps a minuscule bit inwards. That will restore proper contact between the pins on the Gator and the clamps underneath, and get rid of the intermittent noise.

If that's a bit scary, send the board back to me and I'll coat the pins with a slight dab of solder, which will sort out the crackle. Even if you have a soldering iron, don't attempt tinning the pins yourself unless you are very skilled. Tinning those pins is not as easy as it seems. A bit too much solder, and the pins won't go into the socket underneath..

If you need pictures on the first suggestion, let me know and I'll drag myself out of my sick bed to the workshop. Yep, I got a bad flu for weeks now, but luckily my staff are taking care of business for me.

Hi Stan, sorry to drag you out of your sick bed! To be honest, now you mention it, the fit wasn't that tight, but I guess this is a side effect of fitting X circuit into Y space.. My soldering skills weren't that great 15 years ago, and I'm guessing that 15 years of non-use won't have helped! I'll take it back apart and see if I can sort it.. It's all a bit academic now as my newly "repaired" Denon D2000s have just fallen apart after 2nd use I might have to give Tirna a call and ask them if they wouldn't mind doing the honours rather than shipping it all over the country!

Get well soon Stan!

[Cubeman]

Stan, get well soon!

Read the complete topic and this mods sure seems kike one I would like to get for my 7520!
Send Stanley an PB to ask how and what

[magiccarpetride]

It's the best I have heard my D7000 and HD800 sound to date. I managed to pick up some detail in musical passages I thought I had explored to the full.
Time for a retake on all my test tracks .

Finally managed to join the fray and now it's time for reevaluation and the retake on my entire music library.

Before I jump to any premature conclusions, wanted to ask the forum what's the realistic burn in time for the Gator board? I wanna give it full justice, so I need to be sure that I've given it a fair fighting chance. (although, judging from the first impressions, the gatorized Caiman has no reason to fear any competition)

[Labarum]

what's the realistic burn in time for the Gator board?

About the time it takes to switch on and sit down.

[Alp]

I am a newbie but thought I'd give my Gator experience.

I got my Gator last week but the output was just too high and causing clipping in my pre-amp (the standard Caiman board is fine with it). Stan very kindly allowed me to return the board and will refund.

Meanwhile, I have gone passive since I do not use the headphones but use both fixed and variable outputs. The variable output still works and is, err, variable (despite suggestions otherwise). The Rubycon caps cost 2 quid and sound excellent, certainly the cheapest and one of the best upgrades I have done...

Cheers

Alastair

[Cubeman]

Got my Gator mod yesterday and installed it last night.
Must say it sound very very good, quite a bit better than the original board with THS4032 OpAmp I think.
Stan kindly included a LM4562NA OpAmp with the board and I like it!
Bass seems more controled and the soundstage appears a bit wider and very full.
back-to-back testing is a bit hard so I won't attempt that, but this mod seems a very good one right from the box

Thanks Stan for this great mod!