Pars

That one is nice and clean Colin. Fun toy

Ooops, guess I misunderstood you. The transformers are intended for I/V use? I assumed they were just for SE->bal conversion. I don't think I even want to try transformer I/V.

Mouser it is! Looking at the schematic for these (R31-R34), it appears that the CCS's are setup for ~4.5mA, so that is all that is running thru these (assuming I calculated this correctly... 1.6V LED - Vbe ~ 1V / 220 ohms). Footprint is identical to the other leaded/SMD resistor combos, so I am using 1/4W PRPs here.

Marc, I might take you up on that (transformers), for a listen. In order to get a sense of how much these would be should I like them so much I felt the need to buy some, what are they? Sowter? Filburt suggested replacing the ad8599s with ada4898-2s also.

2SA1145 / 2SC2705? Where to buy? I just looked thru my stash and don't have enough of these to do a pair of boards. Any suggestions on where to buy these? I assume Y grade is what I want (not O)? B&D has a few (only 6 SCs), and high price. Mouser has O grade for really cheap. Any other sellers? Anyone on ebay that can be trusted?

Just found a setting related to View New Content since last visit or View New Content Unread... think that did it.

Happy Birthday Grahame!

WTG Todd and all! One minor nit... I assume the View New Content in the upper right is the equivalent of view new posts in the previous iteration. When I hit it again after reading a topic (last post), it again shows that topic, but with no new content. Apparently not marking it as read.

Marc, From a previous post, this is the current recommendation? The series resistor is R62. This is not shown in the Eagle files I have from Jacob, which must have been a bit prior. My eagle files also have TO-220 vregs for the servo, etc. on it, which are not used if you are using the OPA445s for the servo opamp. The board itself has positions (unmarked) for TO-92 regs (7815/7915?) on it. I am going to jumper these and go with the OPA445. I am making updates to the BOM as I go. Also, I was missing the 620/680R, was short on 5K and 30K resistors, so when I did my Partsconnexion order, I used Dralorics here (626R, 5.05K and 30K), which are 0.25% or better resistors. Saved me from making a Mouser order, though that will still happen EDIT: anyone have the final Eagle files? EDIT2: For the 10R resistors, could we use 1/4 or 1/2W PRPs? Or do these need to be 1W? (Reason: I have some 1/2W PRPs)

I'm getting ready to build up one of Colin's tooleaudio I/V stages to put into my Rotel RCD-991. This is a dual PCM-63P player with pcm100 filter. I have currently been listening to it modded with THS4031s for the I/V stage and AD8599s doing the buffer/bal conversion. stock output stage: U302 is the single I/V opamp, U306 is the buffer/conversion opamp (dual) and U304 is an anti-aliasing opamp (socketed now, but not populated. I am trying to decide whether to Retain the AD8599s as buffers/conversion Replace the AD8599s with different opamps Use transformers? If so what? Other? I want to retain the muting relay functionality. The markup below is a first stab at what I think needs to be removed (green) as well as the output (to I/V stage) and input (from I/V stage) back into the player. DC coupled, so the coupling caps will be removed and jumpered. Any suggestions welcome.

Seems like russ has spent the last few years getting bitch slapped for claims made...

Happy Birthday!

Heh. Almost fell out of my chair... R19 and R20. I guessed right. And thanks for reminding me about that schematic as I had forgotten about it. The FB points clear up (somewhat) what is going on with the feedback loop choices. I put stake pins and 2 pos jumpers on for the "switch" for the feedback.

Marc, Before you leave, could you answer one of questions from post 1247?

Looks good Marc. Just needs a blue LED

I got some resistors last week (Parts Connexion sale), so am still working (slowly) on mine. I am going to socket the gain resistor (R55?) so I can more esaily play around with it. I do not have all the parts yet BTW, so don't expect any fire in the hole from me for some time... I'm trying to build these up as much as possible with stuff I already have. Since I am only using half of the output devices, any recommendation as to which positions on the board to use? At least I think I only bought that many FETs from you Marc? You can tell how much looking in my parts stash I have (not) done...

Happy Birthday Luis!

I keep viddying images of Alex (clockwork orange) listening to Ludwig Van...

Congrats Chris! Sorry about the refrig problems, but that one looks nice. Appears to be a Whirlpool, which should be good. Congrats Colin!

Is this still using the TDA1541A DAC chip in it?

WTG Craig! And yes, this thread has been interesting to follow; top notch work.

I was taking the 19% VAT off for US centric peeps 979 € = $1286 (xe.com) -19% VAT = $1041.66 approx.

b-DAC Features & specs • USB, SPDIF and optical inputs, low jitter SPDIF output • Balanced and single ended outputs, including volume control, drive your power amp directly • Low jitter Tentlabs clock (<1ps rms jitter) feeding the sample rate converter and dedicated reclocking stages • 12 independent supply regulators • SRC4382 upsampler, selectable sample rate • 24 bits 192kHz PCM1792 DAC, all inputs reclocked • -117dB distortion at 0dBfs (thd 0,0006%) • Selectable filters and phase • All functions remote controlled • Striking design, includes milled aluminium front panel and stainless steel cabinet Updates • Expected delivery: next batch mid January, 3rd batch early March • Retail price: € 979 (19% VAT included). Order now ! So, $1043 + shipping if I calculate that correctly.

^ OK, great. See Steve, I knew it would be a cool one

I just assumed you had deleted a 2nd post in this thread by Mr. Buick and if so, I wanted to see it. You did nothing wrong...