Pars

I must be dense... the "Y" part

Seems to not be finished... What are thoughts on RJM's stuff on diyaudio, particularly the phonoclone?

Yep. 27" wheels are ISO 630 while 700c are ISO 622, so you will need 4mm more reach on the brakes. Sheldon Brown (RIP) has a section on his site regarding cold setting. Your Panasonic was probably already 126mm for 6 speed. Spreading a 120mm 5-speed frame requires a bit more care, but you are still only opening it 5mm per side.

You can use some appropriate shoes (non-cleated) with your current toeclip/strap setup. Adidas Samba soccer shoes apparently work pretty well. The old Avocet shoes were great though (model 30), used to win RAAM in the '80s. As for the wheels, what kind of hubs? You could rebuild them with 700c clincher rims (Velocity, Mavic, etc.), new stainless spokes, etc. This would open up your tire selection, though you can still get some tires in 27", such as Panaracer Pasela. It wouldn't be much of a stretch to spread the rear to 126mm for std. 6 speed / ultra 7 freewheels. You would have to replace the axle for the rear hub with the appropriate length and increase the spacers a bit for that. The frame could be cold set to 130mm for a modern group also, but getting harder to find in silver alloy. Stuff like what jose just bought doesn't look at home on a vintage frame. Wiggle / Ribble / Probikekit, etc. have pretty good pricing on many groups, but you will also need wheels. Or grabbing a donor bike would be the most cost effective. Should all be English (BSC) threading. Many time you can use the existing crankset, though the modern ramped ring ones will shift a bit better.

Any recs for a decent cheap phono stage? DIY fine as well.

Very tasteful build John!

Great news on Andrew!

Strange... I also have an original Dynalo (built on one of Justin's headamp boards, back when he sold them), plus another one that is built on rev. b/c boards, but powered with an Elpac wallwart. While I still don't think the SUSY version sounds massively better, it is at least as good, and certainly not inferior. My SUSY is using the FET input (K179/J74), and a 10K pot. What is your biasing on the SUSY? Mine is using +/-16V supply IIRC, and running around 17mA. I don't recall what I have in there for resistors, maybe 301R? Also, I recall that I was not impressed with the SUSY initially, but had some pot wiring problems. Once corrected, it sounds very good.

Dan Gardner was the one who actually did the Rev. b and Rev. c boards. He isn't on head-case, but you might be able to contact him on that other site (you know the one). I don't think I ever had the gerbers and I don't know if Kevin ever did or not. Dan might still have them. I think his user name there was dgardner, but I could be mis-remembering.

Here is the 4CP601 only board that Michael requested, along with the Gerbers for both the dual CP601/CP2500 board and the CP601-only board. Change the extension from .pdf to .zip (HC won't upload zip files). TKD 4CP601 only.pdf TKD 4CP board.pdf

Happy Birthday Jack! Hope all is going great, and you have a great one!

Stupid question time (don't slap me!). For a dual secondary transformer, could you wire the secondaries together in phase (1 end of one secondary to the opposite phase end of the other secondary), and use that as the "center tap"? Va 0a Vb 0b Tying 0a to Vb for the CT...

Hmm, hadn't checked in awhile 125.7 up / 23.7 down

lead free is bollocks, based on bollocks, IMHO

Center image is a 4CP-601. Right image is a 4CP-2500. As far as the board layout goes, do you guys more experienced with PCBs and fabs think that the 0.1mm oversize on the slots is enough, particularly considering thru-plating? Or should I go a bit bigger. I haven't measured the pin size on the 2CP2500 I have downstairs, and was going by the data sheet. EDIT: Michael, I want to adjust the board size and spacing to make it as small as possible. I assume the last one I posted, with the split ground planes, is the one that all of you want?

Split ground planes, all traces on bottom. Labeled. Let me know what else...

I doubt it. If you notice, the section mapping between the 601 and the 2500 is: 601 2500 2 1 3 2 1 3 4 4 The two top layer traces (section 3 on the 2500 to section 1 on the 601) could be routed on the bottom layer but they would have to go on the outside of the connectors and would be fairly long traces. The grounded pins on the pot sections for the 601 would also not correspond to a "channel". Tell me more about your desire to have the separate ground planes, and what you feel constitutes a "channel". My thoughts had been, as was done on Birgir's boards, to have the inputs on the right labeled as I1-I4 from bottom to top on the right side, and the outputs similarly on the left. I1/I2 would be a channel (+/-) and I3-I4 would be the other channel. As you can see above, if using the 601 pot, section 1 of the pot would be grounded on the L channel, but carrying the R+ signal (I3).

Re routed, still need to add labels, etc. Gerber looked OK (I think), but need to verify with board house how they want the slots indicated. They are on layer 46, which is milling in Eagle. Pins are 2.5 x 0.4mm, so made the slots 2.6 x 0.5 mm.

I might be able to make it work. I decreased the pad size a bit on the 2500. Slots are defined in milling layer 46. I will need to switch the sections of the 4CP601 to the 4CP2500 since the 2500 overlaps or touches sections 2 and 3 of the 601. I haven't generated a gerber yet and taken a look at it to see if the slots are showing up or not. EDIT: board is about 46x47 mm currently.

Yes, but I've always liked these pots, particularly compared to the RK27. Not sure this is going to work. Due to the slots, the pads have to be oblong. I initially can't get clearance on the middle two rows of pads vs. the 601. The center pin on the 2500 on these rows overlaps the outer pins on the 601. I'll keep playing with it, but I don't see any alternatives if you want the pots to be coincidental (close).

Happy Birthday!

I could use pads with 2.5mm holes in them, but a lot of solder fill and not great mechanical integrity. Looks like getting Eagle to do pads with slots could be somewhat "fun". Might look at diptrace, though I've never done a full board with it, nor created new parts.

Good point Marc.

From experience, you really want to limit soldering on these. The pins are 2.5mm x 0.4mm. I should be able to create a pad with a slot to fit those. Caveat: I've never tried doing that Here is the board so far with just the 4CP-601 on it, no labeling or anything. Inputs on R, Outputs on L:

Keeping it the same would mean supporting both pots, wouldn't it? Oh wait, I hadn't seen the mention of the CP2500 series. Those might be a problem as far as the pins go, as I thought they were solder lug (at least the ones I have are), and not really designed for PCB mount? I'll dig up the datasheet.