Hmmm 6BH6's? I got plenty of those. Possible equivalent to 6CB6? 
Edit: Yep. After going over the datasheets, I dropped a pair of 6CB6's into the 8b. Works. Sounds nice too. Real nice.
Edit: Yep. After going over the datasheets, I dropped a pair of 6CB6's into the 8b. Works. Sounds nice too. Real nice.
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Peter - Nice measuring amp! Thanks for the write-up. However, I'm a little puzzled by the output from your spec an. What causes the LF noise (<1-ish kHz) to be 15 dB higher than the HF noise? I would expect 1/f noise to have a slope to it, but in your case, it's more of a shelf.
Are the spikes around the carrier frequency and 2nd harmonic IMD products of the power supply ripple?
~Tom
Are the spikes around the carrier frequency and 2nd harmonic IMD products of the power supply ripple?
~Tom
If memory serves, 0.75".
Interesting, the particular people who have jumped on this project. Pete really HAS designed an Engineer's Amplifier.
Interesting, the particular people who have jumped on this project. Pete really HAS designed an Engineer's Amplifier.
I received mine today also, even with the post office doing its best to destroy it. One corner of the envelop was missing and the board was exposed. The board seems to be fine though.
Alan
Alan
I got mine today too. The *%#&ing postman stuffed the envelope in the black mailbox (no it didn't fit, so he made it fit) so it spent about 4 hours bent in the sun baked mailbox. The board now has about 3/8 inch of warp in it. There are plenty of mounting holes to straighten it out.
Yes, they measure 3/4 inch. No, the sockets that I have don't fit. Yes, they can be persuaded to fit. The 12 pin sockets that I have are plastic. I wonder how long it will take for me to melt them!
Observations:
I do have some Panasonic 47uF 500 Volt caps that fit the board. Digikey part number P7442-ND, I only have two so I guess I 'll be ordering some more.
The green screw terminals that I use on the Simple SE and Simple P-P don't quite fit, but in some cases like the input connections they can ** persuaded to fit.
The leads from some monster 300 watt mosfets that I got on sale (TO-247 package) don't fit the holes in the board. Do not force things into plated through holes.
Yes, they measure 3/4 inch. No, the sockets that I have don't fit. Yes, they can be persuaded to fit. The 12 pin sockets that I have are plastic. I wonder how long it will take for me to melt them!
Observations:
I do have some Panasonic 47uF 500 Volt caps that fit the board. Digikey part number P7442-ND, I only have two so I guess I 'll be ordering some more.
The green screw terminals that I use on the Simple SE and Simple P-P don't quite fit, but in some cases like the input connections they can ** persuaded to fit.
The leads from some monster 300 watt mosfets that I got on sale (TO-247 package) don't fit the holes in the board. Do not force things into plated through holes.
Well, I'm a polymer chemist.😀 But I've fooled people into thinking I'm an engineer...
For those that have assembled a Simple SE, it looks like this board gets built "backwards." The tube sockets go on the side of the board that does not have silkscreen (lettering) and the components go on the side with silkscreen.
Fairchild mosfet sub?
Digi-Key doesn't stock the Fairchild FQPF8N60C (Q1,Q2), but they do have the FQPF8N80C. Other than the higher voltage rating, the 80C looks pretty close in specs to the 60C.
Ok to make this substitution?
Thanks,
Jeff
Digi-Key doesn't stock the Fairchild FQPF8N60C (Q1,Q2), but they do have the FQPF8N80C. Other than the higher voltage rating, the 80C looks pretty close in specs to the 60C.
Ok to make this substitution?
Thanks,
Jeff
I've shared my Mouser project BOM. As of this writing I've left out the chassis mounted parts. The capacitors appear to be back ordered for now, but it shouldn't be hard to find alternates if in a hurry.
Perhaps someone may wish to share an alternates BOM.
Perhaps someone may wish to share an alternates BOM.
I've been looking for somewhere to use this SCR heatsink -- it is reminiscent of some Norsk invader, or distant relative of Siegfried:
An externally hosted image should be here but it was not working when we last tested it.
Good idea! If mounted instead of an original one it will be much more effective than in the original design, even though not the most effective, according to fin orientation for convection flow.