Slewmaster - CFA vs. VFA "Rumble"

[ostripper]

I think I'm seeing a pattern here. You're from moonshine country. Valery's from Vodka country...

Yes , but now it's legal. Local distilleries found out about my process control "magic" ,
I built them a PC controlled process (free samples now).

I wish I knew the arduino then , shiners in the woods would have "21st century"
distillation.

My grandma (from the Ural's) always had the Vodka under the sink (medicine).
US Vodka gives me a headache - legal local moonshine = heaven (NO after-effects).
As far as a pattern - It helps to elicit that "outside the box" thinking.

OS

 

[ostripper]

What are you lacking for parts still? I think I forgot to send voltage regulators with that last shipment.

For my 5 pair main stereo boards , the 4.7R stoppers @ 1/4 w are good - but I have
only 13 of those. I ran the math - the 5 pair stoppers will see .21W @ 2R clipping
with NJW0281/0302's.

The MT-200's are another story - lower beta , they will need .5W/4.7R + on the sub amp.

The taps are cool - I never seen one like that 6-32 (fluted ?).

My "bench test" now - just 40-0-40V with the wolverine .... test all 6 OPS's (drivers set for 1 V vbe) and jury rigged feedback.
Then , with KNOWN good OPS's set to a known current - plug in the "spooks".

Still need the extrusion for the sub - BTW , your plates fit perfectly.

OS

 

[jwilhelm]

For my 5 pair main stereo boards , the 4.7R stoppers @ 1/4 w are good - but I have
only 13 of those. I ran the math - the 5 pair stoppers will see .21W @ 2R clipping
with NJW0281/0302's.

The MT-200's are another story - lower beta , they will need .5W/4.7R + on the sub amp.

The taps are cool - I never seen one like that 6-32 (fluted ?).

My "bench test" now - just 40-0-40V with the wolverine .... test all 6 OPS's (drivers set for 1 V vbe) and jury rigged feedback.
Then , with KNOWN good OPS's set to a known current - plug in the "spooks".

Still need the extrusion for the sub - BTW , your plates fit perfectly.

OS

Those 4R7s are 1 watt small frame if they are the ones I think I sent. It should say right on them. I don't trust them either. I'll send some real ones down.
All those taps are designed specifically for aluminum. That #6 3 flute one works great for thick metal. That M3 one that looks like a thread chaser is great for sheet metal.

 

[ostripper]

Those 4R7s are 1 watt small frame if they are the ones I think I sent

Oh , in the new bag ? Nope - lowest value in that bag is 47R.
Many fell out of their tape strips - those are also 39/47R's.

So , I have 13 1/4W 4.7's - need 7 more - no 1/2w's at all.
OS

 

[jwilhelm]

I must have missed them. I thought they were in the first box.

 

[jwilhelm]

100 resistors and a few regulators are hopefully on their way.

 

[ostripper]

I must have missed them. I thought they were in the first box.

All is treasured and golden to me - (below) .. I measure each group and even
sort the "orphans" - No missed parts/mislabled ...or waste.

OS

 

[jwilhelm]

All is treasured and golden to me - (below) .. I measure each group and even
sort the "orphans" - No missed parts/mislabled ...or waste.

OS

You sure shrank that pile down! That was a mess of components.

 

[ostripper]

You sure shrank that pile down! That was a mess of components.

Oh no , the pile is bigger - but all sorted and tested like that.
No unlimited resource like dear friend Jay.
Actually used about 3/4 of everything. Have all 6 OPS , 2 spooks , 1 wolverine
DONE - ready for "magic smoke" .

PS - even dived into my original stock. 6 amps (and protection) take a lot of parts !!

OS

 

[ostripper]

I have finally figured out everything with regards to the credit note (got a letter from them today). So I will place an order for snap-in caps in the nearest days.

Thank you , dear friend Val ! Hey , can I clone your bootstrap VFA ??
I'll put yer name on it ! ( it is a good design - servo it and the "thump" will be gone)

OS

 

[jwilhelm]

Modular Supply

Does anyone see any issues with this supply?
EDIT I just saw the inverted diodes.

 

[jwilhelm]

Lets try that again. 89 x 123 mm

 

[ostripper]

let's see ...

Multi-pitch 4 cap , to-220 diode chassis mount , bleeders , snubbed ... with
ability to use external bridge.

Very fat traces- 20a/1oz.
WAY better than Ebay cheapo's.

OS

 

[jwilhelm]

I think I'm going to do another with fuse holders for the outputs. Definitely larger though.

 

[ostripper]

21'st century amp ?? (hard work) ...

So many choices - like Walmart ...

I decided to go with Adcom's grounding setup. (below)
"Buried" my star ground near the trafo - had to split the trafo AC out to the 2 bridges with the euroblock.

Will have it wired to the point of initiating a "controlled startup"(PS) with the Arduino.
The taps were VERY good , especially that "fluted" one. Everything fits .
The heatshrink is strange - glues itself to the wire ? Better quality stuff than in
the hardware store/radio-shack.

This will be tight like the Genesis stealth amp (but way cooler).

OS

 

[ostripper]

I think I'm going to do another with fuse holders for the outputs. Definitely larger though.

Maybe for a testing rig PS , but most have the fuses on the OPS ? Why be that
redundant ?

OS

 

[jwilhelm]

Maybe for a testing rig PS , but most have the fuses on the OPS ? Why be that
redundant ?

OS

I've just finished Valery's CFA-CFP. No on board fuses. Personally I think fusing should be at the supply anyway. Why not protect the supply from a wire that has gotten chafed or pinched somewhere? It's my automotive background kicking in again.

 

[jwilhelm]

So many choices - like Walmart ...

I decided to go with Adcom's grounding setup. (below)
"Buried" my star ground near the trafo - had to split the trafo AC out to the 2 bridges with the euroblock.

Will have it wired to the point of initiating a "controlled startup"(PS) with the Arduino.
The taps were VERY good , especially that "fluted" one. Everything fits .
The heatshrink is strange - glues itself to the wire ? Better quality stuff than in
the hardware store/radio-shack.

This will be tight like the Genesis stealth amp (but way cooler).

OS

It's looking good so far.

Yes that heat shrink has glue in it. No repositioning after. It's rare to find adhesive shrink tube that's flexible.

 

[ostripper]

I've just finished Valery's CFA-CFP. No on board fuses. Personally I think fusing should be at the supply anyway. Why not protect the supply from a wire that has gotten chafed or pinched somewhere? It's my automotive background kicking in again.

I don't think the supply would feel a thing. I actually pinched/ shorted these
big PS's out accidentally .... the discharge usually partially melts the wire while blowing
the main AC fuse. Even that little 10A tabbed bridge PS survived this a few times.

OS

 

[jwilhelm]

I've always been taught that fusing belongs at the source. Fuse again where it splits for distribution. But then again quite a few things are different in audio than the rest of the electrical world.