Gator aid. Or how to get the most from your Gator.

[StanleyB]

Yes folks, it's that time of the year when I get some, at first thought, strange email request that on further investigations turn out to be useful. In this case it has been about the Gator. I'll skip the preliminaries and go straight to the finals .

Non-headphone users who own or are looking at a Caiman/Gator combination:
The choice of opamp is unimportant. So you can stick one of the LM4562 from the original PCB in there.

Headphone users with Caiman & Gator:
The AD826 wins on all accounts so far. No messing about with special adapters (i.e. THS4032 ) or bending pins ( i.e. LM4562HA).

Non-headphone users with TC-7520 & Gator:
The original NE5532 is good enough in the headphone slot.

Headphone users with TC-7520 & Gator:
The Caiman PSU or any good 15V PSU like the linear one from Maplin is a must.
Opamp choice, after a lot of experimentation, is the LM4562NA as used in the standard Caiman. I have tried things like the AD826 and THS4032 instead, but the TC-7520 sounded far too dark and bass heavy. Good for getting my D7000 cans to rattle my skull when fed with some bass tracks, but Norah Jones sounded drunk and randy. I prefer a more even handed sound...

If you must have more extended bass (down to about 5Hz on my scope ), on the Gator there are two sets of empty components holes. It's obvious they are for capacitors. You can try a set of 100uF or even 220uF non-polarized caps. Don't use polarized caps.

Swapping out the caps on the Gator for a different type:
DON'T. The first and only person to have tried that has had to acquire a new Gator PCB.

Changing the gain on line out and headphones:
I'll come back to that at a later stage if there are sufficient interest. The current output levels are designed to be within the CE limits, but the line and headphone output especially can be adjusted for a different optimum gain setting, depending on the impedance of your headphones. I use one Gator set up for my D7000 and K701, and a different Gator set up for my HD650 and HD800. But not everyone would need to be so pedantic as me.

[slate]

I can only speak for myself but I prefer Norah Jones drunk and randy

[Maximum]

Personally I like the AD826 at the moment with the 7520, but I'm using Grado 325is with G cush pads which aren't very dark sounding anyway and bring over a lot of detail. LM4562HA, AD826, and OPA2107 are my favourites. The OPA2107 smears detail a little too much even though it sounds nice. LM4562HA can be a bit bright in the highs at times but can sound very deep and wide with good bass. AD826 is the king of detail but the bass can sound a little lacking in warmth at times, and can show up some harshness on recordings, but it's very clear.

I'm still using the 12V PSU though so I want to upgrade. I'll probably plump for the maplin one but I'm not sure which connector I need into the DAC or whether I really want a bench supply like I'm in a lab.

[StanleyB]

Perhaps I should do an upgrade kit for the TC-7520, comprising of the Gator, opamp, and Caiman power supply?

[Maximum]

Hmm what is the going rate for the Caiman power supply anyway Stan?

[DSJR]

One of the things that an old mate of mine showed me decades ago is how important "infra bass" can be if dealt with carefully, adding realism to the soundstage. Leading on from this, I think it would be a good idea to take the Gator response as near to DC as possible, as long as this doesn't cost in terms of potential instabilities or distortions.

[HighFidelityGuy]

Hi Stan. On the subject of the bass extension mod, does the quality of the capacitors matter much? Also, what difference does the value of the cap make? Is it a case of the higher the value the lower the bass? Cheers.

EDIT: Also, I've just noticed that the spaces for these caps are over on the headphone side of the board. Is this mod just for the headphone output or for everything? Cheers.

[kininigin]

Perhaps I should do an upgrade kit for the TC-7520, comprising of the Gator, opamp, and Caiman power supply?

i would be interested in an option like this,maybe with dac chip upgrade as well.Would this be something you could do stan?

[Paul]

Perhaps I should do an upgrade kit for the TC-7520, comprising of the Gator, opamp, and Caiman power supply?

I thought you already did!!

I must say that this option is what I have and it sounds absolutly fantastic.

Thanks to Stan for suggesting this upgrade for me, I'm well chuffed with it.

Paul

[StanleyB]

Hi Stan. On the subject of the bass extension mod, does the quality of the capacitors matter much? Also, what difference does the value of the cap make? Is it a case of the higher the value the lower the bass?

I have used 100uF and 220uF. They have to be non-polarized and of around 16 to 25V. You might to place them at a 90 degree angle so that they can fit.

Also, I've just noticed that the spaces for these caps are over on the headphone side of the board. Is this mod just for the headphone output or for everything? Cheers.

The mod is only for the headphone.