The MONGREL (supersym II)

[ostripper]

Just an example of the perfection you can get with genuine HP toner and a little "feel" for the process , below are the "AX" boards .. natural light.
most of the visible inperfections are toner blobs .. one real bridge , scrape with trusty needle punch , VERY usable board... these are the first ones I did!!
OS

 

[jkeny]

Well done, looks good, how small a trace width could you reliably get ?

 

[keantoken]

I'm willing to bet those 680nF caps are stacked polyester/polycarbonate film. This intrigues me because polyester (or mylar) is generally considered okay for audio and polycarbonate excellent (pulls out fire blanket). This is only what I've read though.

Dielectric abbreviations:

MP metallized paper
MKT metallized polyester or Mylar
MKP MFP metallized polypropylene
MKC metallized polycarbonate
MKS metallized polyphenylene
KT polyester foil
KP polypropylene foil
KC polycarbonate foil
KPS polyphenylene foil
KS polystyrene foil
PE polyester
PP polypropylene
PC polycarbonate? I've never seen this used though.

- keantoken

 

[ostripper]

I'm willing to bet those 680nF caps are stacked polyester/polycarbonate film. This intrigues me because polyester (or mylar) is generally considered okay for audio and polycarbonate excellent (pulls out fire blanket). This is only what I've read though.


- keantoken

thanx for that , I am still reclaiming parts (lots of multilayers) from my nightowl trip.
OS

 

[keantoken]

I said that because Kenpeter sent me some 1uF caps that look exactly like that. His description reads "Panasonic ECQ-V". You might look up the datasheet to make sure.

- keantoken

 

[ostripper]

minor screwup on the AX

I like my LED's , I did not separate the trace for my CCS confirmation LED on the AX's... I fixed them (below) and will update the AX package soon. One could just leave out the LED and the board would work as advertised.
OS

 

[keantoken]

I found the datasheet, but it says nothing about polycarbonate. Maybe Kenpeter marked the package wrong.

www.panasonic.com/industrial/components/pdf/ef040_ecqv_dne.pdf

- keantoken

 

[keantoken]

Oh, I've been looking through my film caps and it turns out PMD also signifies polypropylene. I had been ignoring these blue caps because I think they're normally used for mains filtering or decoupling, but I wonder if they have value in audio.

www.paktron.com/pdf/PMD.pdf

- keantoken

 

[Bigun]

The winner of the toner transfer test is........ THE MAGAZINE PAGE !!

Jeez, deja vu. After I found that the fancy paper was crapola without a laminator I also discovered that magazine paper was the one that works best. I also discovered that it works even better if you put the board on top of the paper and the iron on the top of the board rather than having the board on the bottom. Use kitchen towel paper between the iron and anything else.

I have strong memories of this - the frustration with that awful 'professional toner transfer' cwrap nearly caused my exit from this hobby before it had even begun - swearing blue murder I was.

You might remember - I think you were contributing to my TGM thread at the time...

 

[keantoken]

MPX caps are also propylene. For instance Dain caps at the power input to switching supplies. PMD, MPX, etc. caps can all be had in ranges up to at least 1uF. Some amps use input caps as small as 470nF. If using these caps improves sound quality, it may be worthwhile to increase your amp's input impedance to near 100k to get the proper bass response.

Has anyone tried it? Thoughts? Am I nuts?

- keantoken

 

[ostripper]

Oh, I've been looking through my film caps and it turns out PMD also signifies polypropylene. I had been ignoring these blue caps because I think they're normally used for mains filtering or decoupling, but I wonder if they have value in audio.

www.paktron.com/pdf/PMD.pdf

- keantoken

all the blue caps I have are for snubbing. .001 -.01uF @400-600v
except those blue one on the GX , 5600p @63v "squarish"
OS

 

[keantoken]

I have a few big blue caps just like that, more stashed somewhere. Here is a 390nF and 220nF. Maybe you weren't as lucky as me.

- keantoken

 

[ostripper]

I have a few big blue caps just like that, more stashed somewhere. Here is a 390nF and 220nF. Maybe you weren't as lucky as me.

- keantoken

Just lucky in the MKT/KT area (below)
as far as value in audio ... ZOBEL bypass /RF HF duty!!

OS

 

[keantoken]

One of those caps is marked MPX, that's polypropylene, isn't it?

- keantoken

 

[ostripper]

One of those caps is marked MPX, that's polypropylene, isn't it?

- keantoken

Yes , made to bypass switching supply "hash" ,very low ESR.

Someone mentioned disbelief that I really use a paint program so here goes..beginning to finish
(pix 1+2).
OS

 

[ostripper]

keen... when you are ready , Pm me.. your amps are ready. If you don't want them , I'm sure someone will take them. they have all the OP's , you need the big caps and emitter resistors... all semi's are undisturbed.(below)
OS

 

[ostripper]

Ready to burn some amps !!

All ready for tomorrows audition. I will go step by step with this mystery amp. almost 100% sure all will go smoothly..
A little solid state porn below.
OS

 

[spind]

Very nice looking! I hope they sound as good as you envisioned.

Steve.

 

[sng001]

Power Board with two pairs of OT

Hi OS,

I like your modular design. Although we can recycle some parts but my problem is the test heat-sink looks like Swiss cheese after a couple of build.

I have built a few DIY amps and found that two pairs of OT has got better drive capacity than one pair of OT.

I have done the layout for two pairs of OT based on your PB60LP. I made some minor changes so that I can use the trimpot & output coils in my parts bin.

In order to save board space, the layout is catered for the CPCP-5 type resistors or the standard CR5-type 5W resistors mounted vertically. The VBE multiplier (Q95) will be mounted on top of one of the OT (Q99).

The Power Board (should we call it PB120LP) measures 68 x 125 mm. I will wait for your test results for the GX voltage board before I build.

Cheers, Stanley

 

[ostripper]

Almost ready to do the deed !! Below I use a test Toriod hooked to a junkbox bridge to get 42-0-42 on the main supply of the PB250's. After the capacitance multipliers I lose 2 volts (as expected) to get a filtered 40-0-40 at the voltage board interface. Tommorrow I will fire up the GX's with this test voltage.

Simulating at 40V rails and 70V rail I see VERY minor differances in the circuits behavior.. so this is the wisest way to proceed.

SNG001 , VERY nice board... 2 pairs do work nice... my "frugalamps" all had 2 pair with 56-0-56V rails .. VERY loud and clean , even driving 2 pair loudspeakers in parallel.
OS