Printable View
Thanks for the advice about the Gator board folks. I completed the upgrade to Elna caps on the main board today. It sounds deeper and fuller with the Elna's with more bass definition and control. I'll post more details about the upgrade in an appropriate thread for the Caiman.
The Caiman with Elna upgrades is working, however there is a volume discrepancy between channels. The left channel is approx half as loud as the right. This happens in both the fixed output and headphone output. Has anyone any idea what might cause this?
Is anyone able to tell me which capacitors are in the analogue section of the left (white) channel. I am deducing that this is where the fault lies as the fault is simply a difference in volume between channels. The left is approx half that of the right. However the fault affects all 3 of the outputs (fixed, variable and headphone). If anyone is able to tell me which caps affect this section of the Caiman it would be much appreciated.
Do you have a multimeter? If so the L and R analogue outputs from the DAC chip pass over onto the front PCB via the right ribbon cable (when looking at the DAC from the front). The wires in the ribbon cables are marked on the PCB. You'll see L, R and probably G for ground. If you test the continuity between the ribbon connections and the Gator board's left pin header you should be able to find which pin on the Gator is L and which is R. Then follow the PCB trace from the relevant pin and you'll come to the first coupling cap near the edge of the board. After that it will get more complicated as the signal will go through transistors etc. The Gator's left pin header is for L in, L out, R in, R out and ground but I forget the order. There's a diagram somewhere in the passive output mod thread if you don't have a multimeter. :)
Thanks HighFidelityGuy I will spend some quality time with the multimeter and try to source the problem.
The TC-7520SEG Gatorized Caiman case is about 2mm higher than the standard Caiman case. I did this so that I could get back to trying out some alternative opamps that require an adapter PCB.
My most favourite is the THS4023 opamp. The picture shows the THS4032 with some decoupling mods around it, which helps to control the THS4032 RF capabilities. Note that I am using 10nF for that purpose.
A couple of WIMA caps in place of the standard ceramic caps in the audio path help to give a bit more depth and soundstage in recordings that have hints of reverberations or echo within the recording environment.
http://www.homehifi.co.uk/aos/Gator4032.jpg
The THS4032 has the low bass of the AD826 and the clinical highs of the LM4562. This is immensely suitable for my D7000 and HD650 headphones.
I hope to do a couple of more minor mods on my Gator and see if I can squeeze any more out of it.
Hi Stan,
Keep up the good work - it sounds interesting (sorry :lol: ).
Are you able to make the new lid available as a stand alone item? I ask because some of us have standard 7520 cases into which they have put adapter boards and twin single op-amps. I realise that this would leave a 2mm gap along the front and back top but that would be better than no lid and might aid cooling ventilation ;) .
Cheers,
Dave.
Sorry Dave, but there are logistical problems on that one.
Understood Stan, no problem.
Dave.
Can't you just use a large block of metal as a punch and bash the inside of the lid so that it is proud?
You know I am barking don't you! Woof:band: