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Maybe you can try taking the opamps and/ or buffers off your CDP. Then drive your speakers/ phones out of the DAC chip directly. =) I seriously think there is more than just a 500ohm pot to achieve this direct path thingy.. Perhaps a custom wound tranny from extremely pure silver/ copper wires + dual-gang log pot. or attenuator. Even then, you'd need some form of buffering.

No problem. How big is big?? LOL!

*bump* For all to check the updates on the first thread. So... Is it safe to say that we'd take the free logo on the 0.6L Traveller Classic bottles? If so, we've to decide on the logo & colour to use. FYI, if this order doesn't fall through, I can still help you guys buy the bottles at the prices stated though.

Actually, he mentioned that the OPA2604 has an open-loop impedance of 600 ohms as it's meant to drive cables directly. However, other opamps used in swapping include the OPA2227 & 4556D with lower output impedances. Note that the opamps directly drive the cable without any fet output stage so the output impedance is decided by the opamp & the gain factor. In any case at all, I don't know but paying to experiment with this is, IMO, a big waste of money. Like you said, most line-outs of CDP's are not meant to drive low impedance loads like headphones. So there is no point trying to make a passive post-amp for the headphones. It'd work (if at all) only with selected CDP's or heavily modified ones.

It's a linear regulated PSU, although not very well regulated. But it'd do sufficiently. More capacitance & filter is preferable for removing every last trace of a possible hum though. hehehe... The LM7824 isn't the only 24v regulator. Linear Technologies has 24v regulators too.

The Blackgates in the Rotel & Sugden are standard Blackgates. The NX series available locally doesn't come in the capacitance & voltage that was needed for the Sugden.

That's the ALPS RK500 potentiometer that the company would sell & ship a single unit from Japan just for you if you buy one. Their minimum order for that pot is ONE. The catch is that the pot is a whopping US$500 on it's own!

No other White Stripes CD's but I'm looking to buy some more when I've the time. Bought my copy of Elephant from Heeren HMV. Right opposite Meritus Mandarin!! Guess you didn't visit huh... hehehe

The Rotel does use 2 opamps per channel. Each channel uses a DUAL OPAMP IC. Some units go overkill. Like my NAD. It has a Dual OPAMP for each channel which is further buffered with JFETS.

To use a DC power supply, wire the DC jack to pads V+ & V-. Use a nice diode across the diode pad. You'd want to have a nice 24v, linear regulated power supply that's capable of near 1 amp for this. And it better be of good quality.

OT: YGEM

Looks like I gotta clear up some stuff here. Attached is the image with the various stages marked out. With the exception of Stage 3, Part 2 where the electrolytic caps were replaced with Blackgates. That is not reflected in the picture. Also not in the picture is the wiring of the RCA jacks with individual ground wires to the PCB rather than a common ground wire looping over all of them and then with an individual wire to the PCB ground.

Any teflon insulated copper/ silver wire will do. It's not so critical especially when the length of hookup wire is short.

Is it configured for direct replacements of normal dual opamps? The link says it's reversed.

The resistors don't really change the sound much. The circuit simply isn't simple enough for the resistors to colour the sound. Stacking buffers would give the amp more control of the sound. Chances are you'd get tighter bass. Going from 1 to 2 buffers per channel is good. 2 to 4 is not so noticable. Above that would be a waste of good money. Note that you need enough reserve capacitance for the buffers as well.

I especially like Clint Eastwood. 19-2000 (Soulchild Remix) is quite catchy too. Meh ish currently on diet of: Sum41 - Does this look infected? White Stripes - Elephant Graham Coxon - Kiss of morning

If you intend to use your tube preamp, I suggest using a polypropylene capacitor for C1. I have no idea what kind of drift is on the output of your preamp. If there is sufficient, you'll have toasted headphones.

The resistor from Pin 2 to ground is NOT R2!!! R2 is from In(+) pin to ground. ie. Pin 3 to ground on single-opamps!

Meh correcto! Those are definitely Elna Cerafines.

Moderately like a pseudo-Corda serie w/o crossfeed function.

It's pretty difficult to get the OPA2132/ 2134 series of opamps to oscillate. Guess you got a short or wrong connection on the opamp somewhere. If you used dual voltage rails, you MUST connect the virtual ground (or PS ground) to the audio ground. It's not advisable to change R2 to 10K unless you don't have a pot for volume control.

If you hunt around echoloft forums, some posts do state which audiophile shops to go to for these Browndogs at about S$8 or so each.

I quote from the page:

They could also be Cerafines. OPA627's are compensated. That's to say that they're unity-gain stable.

Keep in mind that the logo printing is free only if the logo is 5cm * 5cm & smaller AND that we make an order of at least 30 bottles. As a guideline, the 0.5L Traveller bottle would be about S$22.00. The 0.75L & 1.0L would obviously cost more. I think most of us will take either the 0.5L or 0.75L though.