Pars

The DC servo really isn't a feedback circuit. However, thinking about it, you do have the negative feedback in place, correct? Don't have the resistor numbers offhand, and I think the 2pf cap is compensation for the feedback circuit. You might just pull an active of each type, or if you have spares, test them. EDIT: R52/53 and 56/57 are the feedback circuit, with C1 and C3 as compensation caps (schematic shows 1pf).

Happy Birthday!

Happy Birthday!

Agreed. The bouncing around part and the amount that it is moving seems to indicate a problem. For something like an I/V stage with no feedback, I see this. For a dynalo/dynahi, they normally seem pretty stable for offset if things are correct in the build, pretty stable meaning it should be easy to get it to +/- 2mV drift without the servo in place..

How is your heatsinking? The output devices need to be thermally stable, although even with that I don't know that you would see 5V output DC offset. I'm not sure if there is an operating points diagram floating around, but it sounds like you may have a wrong part somewhere. Also, the LEDs should be matched pretty closely for V drop.

It took them 4 times to ship me the correct resistor value on an order a couple of months ago. They must have had the wrong values in their location. I had ordered 2.2K RN55s. They sent me 3.1xK the first 2 times. I changed to a 2.21K, they shipped me something else. Finally got it right, but yeah, they seem to be having some problems. I don't think before this that they had ever made a mistake on any of my orders. The other 20 some line items were correct on the latest order.

Road 6 miles after work on the Trek (Raleigh is still in pieces ), 33 degrees, not bad. Still need to make some adjustments to the Trek, like wider bars than the stock ones. Also need to get something else on this for pedals as the platform ones on it suck. It has been so long since I have ridden without some type of foot retention that it feels really awkward. Feet slip all over these things.

^ build a dynalo/mid

Pigmode, hope your back mends quickly. Vicki, take it easy as Chris said. Give it some time before you work up to steeper climbing. Me: Bought a Campy Racing T crankset and Centaur BB (not pictured). Will use these on the Raleigh late summer for something I don't know that I can climb in a 43-24.

Happy Birthday Fitz!

RIP Alvin. Listened to that a bit back in the day, and always liked "I'd Love to Change the World" as well.

I always used TL071s (that is what Justin used for the Gilmore amps). (apologies to Justin for borrowing his pic ) When I was building the pair of cetoole I/V stages for Ryan (recstar24), I found that TL081s worked the best for servo of all the single opamps I had on hand, including OP27s. That said, I would use the 445s for this and not bother with the 15V regs just for the servo.

Guess no one answered you You should be good on the GRs... that is pretty much all that is available. For the FETs (109/389), measure Idss and hopefully they will match OK. There really isn't an advantage to using the duals... some say that being on the same die, they should be matched better. Not in my experience. They are thermally bonded however.

Congrats as well! Thanks for posting this, I'll be looking at it as well.

Happy Birthday Nate!

This was posted on another forum, but thought all of you might enjoy it. Actually gives one hope for things... http://www.viddler.com/embed/70d1d214/?f=1&offset=0&autoplay=0&secret=48017121&disablebranding=0

Happy Birthday Naaman!

Preamps such as the Pass Aleph P use a simple panel mounted pot for gain control, one per channel, separate from a volume control.

http://www.diyhifi.org/forums/viewtopic.php?f=2&t=2260 This might be of interest as far as the ODAC goes. I'm sure it is alright... just alright. Please compare "That" DAC: to one designed by a competent designer: Ciao T

^ This. I have no doubt you'll get back to your old self Vicki!

Happy Birthday Dan!

Ruh roh! I have the Raleigh completely torn down to the bare frame right now, and finally decided to fix what a machine shop fucked up 30+ years ago. I had Raleigh replace the fork, and when it arrived, the crown race seat needed to be machined. Back in the pre-internet days, and a fairly new LBS, they didn't have the crown race cutting tool to handle it. Couple that with the fact that I had no idea about ISO (26.4mm) and JIS (27mm) fork races. Mine was a 26.4mm Campy. I asked for a "loose" press fit. It came back machined down to < 26mm. I guess that is loose Shim stock roughly took care of the problem in this time. Sent the fork up to Chris Kvale in the twin cities. He has it rebrazed and machined correctly:

Any news from our friends at linearsystems?

Happy Birthday!

This sounds really promising Kevin. Are you thinking of keeping the higher power output stage... for a headphone jack?