New 183 build

[dorrisant]

"What's in the box, man?!?"

Seriously, show us you wire organizer. I'm always interested in more ways to do common things.

Didn't mean to derail. Looks very clean so far.

[bepone]

Cheers! Have you used the Epcos? What do you think?

in hi-fi 50w using often Epcos cans 1000uF/300V 2 in series, and all the amps sounds great so i have nothing to say, Epcos is ex Siemens comp.

[Stephen1966]

"What's in the box, man?!?"

Seriously, show us you wire organizer. I'm always interested in more ways to do common things.

Didn't mean to derail. Looks very clean so far.

https://www.amazon.com/dp/B084DM42JS?re ... tails&th=1

[Stephen1966]

Cheers! Have you used the Epcos? What do you think?

in hi-fi 50w using often Epcos cans 1000uF/300V 2 in series, and all the amps sounds great so i have nothing to say, Epcos is ex Siemens comp.

Cool. I noticed Shad had used the Epcos' after I found them. Basically, I was looking for longevity and a high ripple current. In their position - straight after the rectifier - they have a bit of filtering to do.

i-W8399z9-L.jpg

I don't know about the Siemens, but I've also used the United Chemi-Con radials with success. They are bigger than the Epcos. [Edit: Er, no! Just compared them again, the Epcos are bigger ] https://cz.mouser.com/ProductDetail/?qs ... fA%3D%3D

[bepone]

all of them are 30-35mm so you can design distance between them 36mm and all will fit
Epcoss often are found cheap like for 1-1.5Eur and they are long life, reliable, made for professional electronic, so all is satisfied..
I'm using also UCC often, i bought boxes cheaply

[Stephen1966]

Another couple of steps forward today with most of the hardware, tone stack, and underboard wiring here...

1674418263181.jpg

1674418263204.jpg

1674418263229.jpg

[jazzbass]

Hi Stephen,

excellent layout of the relay connections, why didn't you use the Tubetown kit as power supply as in the voltage test but did you use a board like Dumble did?

A hug

Franco

[ijedouglas]

Another couple of steps forward today with most of the hardware, tone stack, and underboard wiring here...

Looking really good! You may want to reconsider zip-tying the master in to the OD coax. I used to do it until I had to change out an OD pot

[Stephen1966]

Hi Stephen,

excellent layout of the relay connections, why didn't you use the Tubetown kit as power supply as in the voltage test but did you use a board like Dumble did?

A hug

Franco

The tube town power supply is just a bit underpowered for three relays plus 7 LEDs when it only puts out 166mA. The power transformer has a 12V tap which will put out 1.5A which is on the safer side. That and a Dumble board (you see in the pictures) is just more robust. A standard ODS with just two relays and two leds would be okay with it.

[Stephen1966]

Another couple of steps forward today with most of the hardware, tone stack, and underboard wiring here...

Looking really good! You may want to reconsider zip-tying the master in to the OD coax. I used to do it until I had to change out an OD pot

Good point. Thanks

[bepone]

Looking really good! You may want to reconsider zip-tying the master in to the OD coax. I used to do it until I had to change out an OD pot

+1
also i dont think wires inside the coax are 100% shielded , maybe better to keep MV out of this group , separated like HAD, to avoid unnecesary coupling..

[dorrisant]

Looking really good! You may want to reconsider zip-tying the master in to the OD coax. I used to do it until I had to change out an OD pot

+1
also i dont think wires inside the coax are 100% shielded , maybe better to keep MV out of this group , separated like HAD, to avoid unnecesary coupling..

Bepone, I totally believe you but would like to know if you could direct me to pictures that show that.

[bepone]

Bepone, I totally believe you but would like to know if you could direct me to pictures that show that.

you can change the OD character of the amp with those cables, at least in my case.. on various dumble amps you can see 2 OD coax bunched, MV separated...i think at least on several pics and different amps i saw this so i thought there can be something
here is 221 from this forum

ods 221.jpeg

[Stephen1966]

Bepone, I totally believe you but would like to know if you could direct me to pictures that show that.

you can change the OD character of the amp with those cables, at least in my case.. on various dumble amps you can see 2 OD coax bunched, MV separated...i think at least on several pics and different amps i saw this so i thought there can be something
here is 221 from this forum
ods 221.jpeg

Thanks! You could be right, though honestly, I have trouble making it out from this photo. I think about the phase relationships and essentially the two coax (from V2a and V2b) could offer negative and positive feedback, respectively. I don't know if it is possible to find to find any shielded cable which can claim to be 100% effective but this stuff I'm using (Belden RG174) claims to have two layers of shielding: 100% coverage, internal aluminium foil (Sorry spellcheck - I'm British!) and, a 90% coverage copper braid over the top. Any emission is likely to be very low.

Interesting questions I did ask though are why not just use coax for the master? And why not? First, I think, the signal is strong enough to swamp out much of the noise in the sound floor there but I also find it interesting that the master out appears to run in parallel, to and from the FX jacks with the PI in, 0.02uF coupling cap (leading, to what would be V3b, grid pin 7). That seems to me, to be a more likely source of positive feedback and why I abandoned the plan of using coax for the master. If it does exploit positive feedback on the way to the PI, I don't want to mute the effect using shielded cable.

[bepone]

Interesting questions I did ask though are why not just use coax for the master? And why not?

If using coax you are killing a lot of heighs.. if not, it is ok.
explanation, worst case:
Master volume 1M on low positions , makes cca 900k resistor in series with the mid viper, which is loaded to coax and has capacitance at least 50pF, you have rollof too early, starting after 1kHz. Plus PI input, long tail pair Miller capacitance.

Master should be at cca 250k to avoid this effect, and loaded with some cathode follower to not to load too much previous stage.. I have already tried output from the CF, 100k and 250k Master volume it is working better than 1Mohm