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View Full Version : Stan's 7520 + gator, my impressions



Krisbee
01-03-2011, 13:04
My “TC-7520 + Gator = ????” thread http://theartofsound.net/forum/showthread.php?t=9552 didn't illicit much of a response, except stick a Wolfson in it, but now I know the answer.

The appearance of the Caiman set TC-7520 owners a “stick or twist” dilemma and while I've followed all the mod threads I sat on the fence long enough to get a bad case of “constipated duck”. I had just about finally decided to send my TC-7520 to be maxed out by Tirna Electronics, particularly after learning Jimmy Dripp was fitting Gator boards on request. But then I thought surely even old margarine fingers (no butter in my house :() could manage to fit one of these?

Ordered Friday lunchtime it was delivered in Saturday's morning post, I couldn't have got it much sooner if Mr.B had come round with it himself. That's what I call service.

Fitting it was straightforward, the only sticking point was the tenacious grip of the pad under the audio pcb which had to be carefully prised free. I re-used one of the two LM4562NA op-amps I had fitted when I first got the TC-7520.

So has the Gator board transformed the DAC? Well, yes I think in a way it has and before I'm accused of over extolling it's virtues, let my try to explain.

Classical music is my thing, from Renaissance polyphony to Baroque and Classical with a smattering of the Romantics and small doses of Elgar, Holst, RVM and BB et al. I have a preference for 18th Century Music played on period instruments. This isn't pipe and slippers stuff, the Baroque can verge on hooligan horns, wild winds, vicious violins and banging bass. There is, for example, nothing tame about the Mozart's Prague symphony as played by the Freiburger Barockorchester under Rene Jacobs, nor can anyone say Beethoven's music lacks passion and drama. What about vocals? There are plenty of Handel arias and duets to die for, sung by some of the best voices around. In short, this is music to test any DAC.

I listen to my system near field in a small study, it's not an ideal room. I'd say it's main deficiencies were that it doesn't do “big”, is bass light, and the upper treble is harsh. Small scale ensembles, and vocals are very good. But large forces are more of a challenge. What bass there is can sound a bit samey. Nor am I hearing, for instance, a great deal of difference between BBC Radio 3 192kbps stream and their 320kbps HD sound. Some of this is due to amp/speaker/room limitations but the treble harshness I put down to the DAC.

So how has it changed with the Gator board?


Treble harshness is far less noticeable – a big plus for me.

Instrument separation is improved – this is another big gain for me. Listening to larger forces, as in concerto and symphonic music, is transformed. For example, it does a whole better job of unravelling the complex contrapuntal lines of J.S. Bach's concerto for 4 harpsichords BWV 1065, that really rocks along now.

Bass is improved. I'm not expecting gut thumping bass, but the bass lines in Classical music are important, whether it's Henry Purcell's grounds, the basso continuo of Baroque, or Beethoven's thundering double basses. Better instrument separation makes the bass lines more distinct and the bass is less “one note” than before.

Dynamics are improved – another big plus for me. There really is a greater sense of musical energy than before, again this is particularly noticeable in concerto and symphonic music, but it is present across the board. Sudden changes in loudness are heightened and there's a great sense rhythm. You really can hear the beat, heart, pulse, or whatever you want to call it, in what is played.

Quality recordings sound better. Now I can hear a real difference between the BBC Radio 3 192kbps stream and 320kbps HS sound, particularly with live music. Basically, better quality source files are just sounding that much better.


I don't know the technicalities of how the Gator may have changed the overall gain or output impedance of the fixed/variable line out of the TC-7520 DAC, and if this is now a better match to my power amp or what. So YMMV, but for a measly £30 the Gator really can make a positive change even in an otherwise stock TC-7520. I don't see how can wrong really by giving it a try.

Now there's just the small matter of a Wolsfon DAC chip, murata regs. and a new 15V PSU ....

Happy listening.

Krisbee
03-03-2011, 12:41
Now I've found and read the entire thread The discrete TC-7520(SE)(+) line output, I see I'm well behind the curve.

But I have a small footnote. Although I have two TC-7520s for use in different locations at home, I didn't attempt an A/B comparison between “DAC as is” and “DAC + gator board” while listening over loudspeakers.

I don't do much listening over headphones, and only have a pair of hd595 which I picked up ½ price some time ago, before any DAC dalliance. They're OK, but are not classical music orientated and I always had doubts about their overall tone, which seemed a little “dark” to me.

It's easier for me to do a direct A/B comparison between my two TC-7520s when fed from my ageing CD player and listening over headphones. The gator works exactly as advertised and headphone listening is a lot more pleasurable.

I've just ordered another gator board now I realise what I have been missing and I won't use the headphones on my 2nd DAC until it is fitted.

StanleyB
03-03-2011, 15:38
I got three of the Gators left. But hopefully the 2nd version will be ready end of next week.

Krisbee
03-03-2011, 15:57
Was I just in time then ;)

Werner Berghofer
05-03-2011, 19:34
Chris,

So has the Gator board transformed the DAC
oh yes, it certainly did. Yesterday I modified my two TC-7520 DACs by adding Gator PCBs with LM4562NA op-amps and Caiman PSUs. These units will be used primarily for listening with AKG K701 headphones.

I think the volume has increased, the music’s fundament sounds deeper and richer, the detail resolution has improved. I’m very happy with the results. However, when comparing the gatorized TC-7520s with the two gatorized Caiman DACs in my home, it’s quite obvious that the Caimans do sound better on the headphone output and with my loudspeakers (Triangle Esprit (http://www.triangle-fr.com/en/esprit/antal/) in my living room, Q Acoustics 1000i (http://www.qacoustics.co.uk/1000i/1010i.htm) on my desk). The gatorized TC-7520s perform really good, but they are no match for the gatorized Caimans.

http://www.berghofer.com/photos/wp/2009/audio_desktop.jpg
My desk

http://www.berghofer.com/photos/wp/2009/musik_wohnzimmer.jpg
The relevant parts of my living room

Now I seriously think about purchasing a third gatorized Caiman for my preferred headphone listening chair in the library. Once you’ve heard music playing through this device you won’t be satisfied with anything else in the same price segment. :(