Pars

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R52/R53 and R56/R57 (200K/10K) dynahibalbjt.pdf

These are the boards; I had seeed run 10 of them. Guess I'll have to build one up and see if it works... The board is a bit larger at 116 x 107mm, so new build only. Mounting holes are inset 5mm (x,y).

I think this is right (and already had some run), but if someone wouldn't mind checking the schematic, particularly around the rectifiers, I'd appreciate it. I had corresponded with ang728 back when he did a multi-output version of the GRLV, and he sent me his layout files. I made some changes to these around: Added dual rectifier banks, supporting TO220 packages so I could use the SiC schottkys as Kevin did on his 35mm cap board Supports up to 35mm main filter caps Outputs will take either 5.08mm LS or 2.54mm LS connectors (i.e. Molex SPOX or KK) Added positions for xfrmr secondary snubbers Removed the caps across the rectifier diodes as they aren't a real snubber and don't do anything useful

Waiting for CSO... Wagner- Overture to Rienzi R. Strauss- Four Last Songs Nielsen- Symphony No. 4 Sent from my iPhone using Tapatalk

Happy Birthday Todd!!! Sent from my iPhone using Tapatalk

I think IIRC that stripe (+?) o the tantalum goes towards the back of the board. Also, I wouldn’t populate the 0 ohm jumpers until you have tested and adjusted the amp. Sent from my iPhone using Tapatalk

^ This. RIP 41.

You didn’t look hard enough Looking at the amp from the front, the channel layout is L- L+ R- R + The two pots by the LEDs balance the +/- for that respective channel. The other 4 pots adjust the channel closest to it. There is some cross action with the other phase but not a lot. Normally you don’t need to do much with these. You can also get yourself in trouble with these if you go too far. If that happens, reset to midpoint (using a DMM on ohms) and start over. Sent from my iPhone using Tapatalk

Well it raises the input impedance for starters. I think Kevin told me you could go 10x on the gain resistor combo and use a 25k or 50k pot if you wanted to. I always left things stock on the ones I built so the users could go to BJT input if they wanted to. I think the JFETs sound a bit better, but I could be delusional... Sent from my iPhone using Tapatalk

I’m not sure if it increases or not. Since everything in a Dynalo mini is integrated. I would think a grounding issue is unlikely unless maybe something to do with the house wiring. And these aren’t prone to oscillation from what I’ve seen. DynaFET is another story... Sent from my iPhone using Tapatalk

^ search back in this thread for some suggestions. Should be easier with the 2oz copper boards than it was with the 3oz from the previous GB (who DID suggest going 3 oz... )? My personal suggestion would be stencil, solder paste and an oven. On another subject: One of the amp recipients that I did a build for has had some problems with his amp since it was delivered on Friday. Here is what he told me: BAL source, SE headphones = slight hiss in left channel BAL source, BAL headphones = no issues SE source, SE headphones = large hiss in left channel SE source, BAL headphones = no hiss in left channel, but turning the pot creates a lot of static So far the suggestions I have made were swap the THAT chips (this is one who didn't opt for the FAR superior JFETs check the source in SE mode for DC offset, and try grounding the pot case. When testing these, I did verify continuity on all of the case panels, at least on the first 2 I built. I never had to do anything as the screws seemed to make good contact. The eject tabs on all of the XLR connectors had continuity to ground as well. Any thoughts? Thanks in advance!

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Happy Thanksgiving all!

^ For the most part. I would populate the (2) 10uf caps shown in the arrows below, as these are pre-regulator for either onboard or offboard. I know Kerry said he populated all of the caps even though he used offboard regs, and they aren't required.

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Wayne and Antonio, What awful news! My condolences to both of you. Sent from my iPhone using Tapatalk

What did you pay for it? That is where I would start...

RIP Stan... ?

Happy Birthday!

Happy Birthday Chris! I hope you have a great one!

Something I noticed in the mini BOM was that the power switch listed (8161SH9AV2BE2) isn't rated for AC power duty. Instead, use either the "G" or "Q", which are both rated for 120/250VAC. Use 8161SH9AV2GE2 or 8161SH9AV2QE2 instead. Mouser stocks the "Q".

The SLX might be slightly stiffer. The seamed Columbus tubing (Chromor, Aelle, etc.) is pretty good riding stuff though. So much so that back in the ‘90s a mag did a test with some riders on identical frames other than material and the Chromor frame won IIRC (think it was Chromor, but it was one of the seamed tubes). The back bike in the picture looks like it was a bit small for the rider judging from how high the seat is. That’s some serious drop! Sent from my iPhone using Tapatalk

Yeah, just seems like the AC voltage measurements on the Fluke 89 at least are RMS. I used my bench HP 3269 or whatever it is for this though. I was just trying to correlate the AC current draw with the DC biasing conditions but I can see that would get into a fairly complex calculation involving factors you mentioned and more probably. Just knowing the current dropped with the heatsinks in place was enough confirmation. And 10mA AC is probably more significant that it seems. Sent from my iPhone using Tapatalk

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