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

[brian2957]

Nice one Dave . I'm using speakers to listen to my Caiman with redbook CD WAV rips and the more I listen the bigger the grin on my face:D. I've listened to a couple of very well known albums now and have to say that this mod is worth every penny and more . I can't wait until tomorrow so I can crank up the sound and really hear my system . BTW I had a similar problem with the
coil . It does fit with some gentle persuasion however.
Brian.

[Frizzup]

http://www.homehifi.co.uk/aos/S4A.jpg

Stan,

Can you give me the specifications of this coil. I already have the bipolars ready to go from my box of parts but need this coil.

Thanks
Frizzup

[StanleyB]

The coil I used so that it would fit in the available space between the two caps close by, is the TOKO 187LY-222J. It is a 2.2mH 13mA coil. But to be honest, I have experimented with the coil size and used a couple different types from my components box between 100uH to 10mH with up to 280mA capacity. The main criteria is that it can handle at least 10mA and that it can fit..

A good reference is HERE (http://www.jabdog.com/toko-8rb.htm)

[barry-potter]

Okay the number of mods available for Beresfords dac's is confusing me somewhat. I have a Caimen. It may be a dumb question but can I do the passive mod and the silmic mod for the gator board or does the passive mod bypass the gator?

[HighFidelityGuy]

You can only have the passive mod or the Gator board, not both. One is a passive output stage, the other is a discreet transistor based active output stage. From what I remember, the Gator was designed to provide a similar level of improvement to the sound clarity as the passive mod but being active. Not all amps are suitable for being fed from a passive output stage. The Gator board also has a slightly better headphone stage than the standard Caimen output board. The passive mod removes the headphone stage. So the Gator board provides the best balance of features, flexibility and quality in my opinion. :)

[StanleyB]

Okay the number of mods available for Beresfords dac's is confusing me somewhat. I have a Caimen. It may be a dumb question but can I do the passive mod and the silmic mod for the gator board or does the passive mod bypass the gator?
If you don't need the headphone output you can do the passive mod with two Silmic caps, and you won't need the Gator.

[tdog]

Hi Stan,

I installed the Silmic caps etc (green film caps and inductor included). I must say that I am impressed. I had bypassed the previous caps with film devices last year which gave a small improvement, but this is much better. More detailed, finely etched and smoother top end (not an easy combination to achieve), seemingly deeper and more authoritative bass. This is only after 30 minutes of listening, so I expect more later.

Many thanks for making this available to us, especially at a great price (cost) - you are generous and kind to do so.

Cheers,
td

[DaveK]

Hi Stan,

Many thanks for making this available to us, especially at a great price (cost) - you are generous and kind to do so.

Cheers,
td

I firmly echo the sentiments in the above sentence with the exception of the bit in brackets. Stan is a business man doing this for a living and I for one want him to carry on doing what he's doing. Unless he makes a profit that won't be possible so I sincerely hope he is not doing it at cost. Even with a mark up Stan's VFM can't be beaten IMHO so there is no need to do anything at cost.
Keep up the good work - and prices ;) - Stan.
Cheers,

[StanleyB]

Unless he makes a profit that won't be possible so I sincerely hope he is not doing it at cost. Even with a mark up Stan's VFM can't be beaten IMHO so there is no need to do anything at cost.
A very sensible suggestion Dave. I shall consider putting the kit on my site.
Mind you, the 2.2nF Vishay is not a night and day improvement for me. I have however tried out a 33nF instead of the 47nF (early boards) or 33nF (later boards). On some headphones the 33nF is better. So I might add that to the kit instead.

[Gints]

Does this kit will improve variable output in the same way as headphone?

[StanleyB]

Yes it does.

[Gints]

Great! One other question. I connected Caiman Gatorized fixed output by Y cable to two amplifiers and sound was distorted (one amp working and other switched off). Is that normal? I tried the same with variable output and sound was ok.

[StanleyB]

When you use a Y-cable you have to take into consideration the fact that you are also changing the output and input impedance of all the items that are connected to that cable. If the amps are not designed to operate at a lower input impedance you would get all sort of possible fault condition.

[Gints]

Will there be no such problems if I use fixed output for one and variable output for other amp?

[StanleyB]

I haven't experimented with that option, but feel free to report back on the outcome of your experiment.

[Gints]

I meant, having connected both fixed and variable outputs is the same scenario for a DAC as Y cable or it is different?
I tried it and did not hear the same problem as with Y cable to fixed output, but maybe if I can not hear does not mean that they do not exist. One amp has 50kohm, other 47kohm input impedance.

I have a miniwatt n3 valve amplifier which is just a power amp with volume pot and I am thinking about should I bypass it and use DAC volume control for both amps, or better no. At the moment other amp is integrated but it will be replaced with studio monitors.

[Gints]

Now it gets weird. I am listening headphones and only one amp connected to dac (switched off). When amp connected to variable output, sound is fine. When amp connected to fixed output - sound is distorted. Tried with two amplifiers, the same thing. If nothing connected, sound is fine. Does it mean that dac must be investigated? Distortion is not a straight way, just in certain places of music.

[StanleyB]

Your amp is shorting out its input when it is off, which is affecting the direct audio path from DAC to amp.
In the variable output path there is a buffer stage that splits between amp and headphone. That one is disconnected from the amp when the headphone is plugged in. So use the variable output if your amp is exhibiting this problem.

On my next DACs I shall remove the option of having a fixed and variable output at the same time, and fall in line with the other DAC manufacturers.

[MartinT]

Thanks to Stan for another excellent chapter in the almost infinite upgradeability of the Caiman. I'm late to the Gator because I found the passive coupling caps so good, but now I have to say the Gator with Stan's mod kit sounds superb and has the visceral welly that the passive version lacks.

So far, having just got it powered up, all is well and the sound is already very good. I'll fire up my headphones later to hear how that side of things perform.

http://www.mtc.me.uk/images/GatorMods.jpg

[Canetoad]

Martin I meant to ask you how you were getting on with your Caiman PSU these days.

I'm thinking of replacing the SuperTeddyReg in mine with a Paul Hynes module as per yours. Still a worthwhile update? :scratch:

[MartinT]

It's a tough one, Bernie, as the SuperTeddy was very good for the Caiman. However, it is more of a filter than a dynamically responsive PSU like Paul's. I feel that overall the PH 1st and 2nd stage regs work in harmony for a very good outcome. There is more welly, slam, whatever, to the PH combo than there was with the ST feeding the Dexas.

[StanleyB]

Thanks to Stan for another excellent chapter in the almost infinite upgradeability of the Caiman.
Let's hope that I can get the 24/96 USB upgrade board working as well :eyebrows:. Unfortunately for me I have an error somewhere in the layout of it:scratch:. But once the Bushmaster is shipping I'll get back to sorting out the TC-7520 series USB upgrade PCB. So stay tuned:).
The Caiman still has lots of bite left in it. There can't be many DACs out there with such a long term upgrade support structure built into them from day one. I wish many more designers did things that way, instead of designing something with a steep declining redundancy built into them.

[Canetoad]

The problem is that they make more profits if you throw out the old and buy a new one. :steam:

I'll be up for a 24/96 board for my Caiman when they're available Stan. Come to think of it, I'll be getting a Bushmaster too. :lol:

[keiths]

I'll be up for a 24/96 board for my Caiman when they're available Stan.

And me... :)

[Gints]

Your amp is shorting out its input when it is off, which is affecting the direct audio path from DAC to amp.
In the variable output path there is a buffer stage that splits between amp and headphone. That one is disconnected from the amp when the headphone is plugged in. So use the variable output if your amp is exhibiting this problem.

On my next DACs I shall remove the option of having a fixed and variable output at the same time, and fall in line with the other DAC manufacturers.

One amp responded well when was switched on, other did change nothing. But I read all thread and saw that others also had the same problems, so it is nothing unique. Looks that I need to use my amp with variable output. I does distort on variable output too, a bit less and only close to max volume on dac. Probably there is somehow involved gain.
If somebody interested amp is Miniwatt N3, input sensitivity 500mV, input impedance 50Kohms, song was Katie Melua I cried for you, around 1min.

[charonme]

I just got a gatorized caiman (with AD826) and when the digital input signal is too loud, I hear clipping and distortion with my headphones even on low amp levels. I tried 3 different headphones. When I replaced the gator board for the original one the problem vanished.