yes.... I Know....I'm starting a #183 build!

[donvan]

They’re easy to source at mouser. Radial, not axial.

You're right, in my post above I meant radial. I corrected it. Even though radial 330uF may be easy to source, I was curious what part number Marcus used since the radials that I used were too tall to stand up.

[martin manning]

Look at so-called “Snap-in” caps. I believe that is what Marcus is using.

[norburybrook]

Look at so-called “Snap-in” caps. I believe that is what Marcus is using.

yes, that's exactly what they are. I'd actually forgotten to order them from tube town or Moser so had to get them from a very expensive high end audio company...hifi collective. they sell caps for $200 each!!!......I paid about £20 for those two with postage etc. I hadn't actually realised they were that small until they arrived, they were the only ones with the correct values on the web site.


I only had to drill 4 new holes and put some eyelets in the board and then connect them up underneath with the bleed resistors in the normal place on the board.


it actually looks quite tidy with these caps I think.

while we're talking caps, what voltage tantalum 1uf cap is OK? I have a 50v but it seems very small physically.


M

[martin manning]

50V will be fine for the presence cap.

[donvan]

Thanks Martin!

[martin manning]

Measure the voltage there when you power up. Should be around one volt.

[martin manning]

Marcus are you going to A-B those NOS plate resistors in this build?

[donvan]

Thanks Marcus. I also had to drill new holes and add eyelets. I do like the small caps you used better than then ones I ended up with.

The good news for me is that I finally finished wiring up my 183 build this weekend. The power supply and preamp are working (verified via the preamp out. No power amp yet due to a bad bias pot. Hopefully zero volts bias didn't damage any power tubes. As soon as I took it out of standby there was a whirring/whistling sound even though I was using a dummy load and not a speaker. I immediately shut it off so hopefully no damage was done. I pulled out the power tubes and after some trouble shooting I found that the bias pot was bad. I'm close.

[norburybrook]

Marcus are you going to A-B those NOS plate resistors in this build?

Martin, I never got them and I haven't heard from Charlie in a while. Also they were low plate values.

I've ordered some strange black metal films from mouser for the plates, they were high quality and expensive I thought it was worth a punt as we say.

M

Sent from my Nexus 6 using Tapatalk

[martin manning]

Well that’s unfortunate. I was hoping to get a good A-B test of resistor sound.

[norburybrook]

Well that’s unfortunate. I was hoping to get a good A-B test of resistor sound.

if I/we ever get these things then I'll do and A/B with my second gen low plate. I have that amp profiled as well so I can do a direct before after setup with the Kemper.




M

[martin manning]

Look at so-called “Snap-in” caps. I believe that is what Marcus is using.

yes, that's exactly what they are... ...I only had to drill 4 new holes and put some eyelets in the board and then connect them up underneath with the bleed resistors in the normal place on the board. It actually looks quite tidy with these caps I think.

I think I might just have to update the board layout drawing to include this option ;^)

[norburybrook]

Look at so-called “Snap-in” caps. I believe that is what Marcus is using.

yes, that's exactly what they are... ...I only had to drill 4 new holes and put some eyelets in the board and then connect them up underneath with the bleed resistors in the normal place on the board. It actually looks quite tidy with these caps I think.

I think I might just have to update the board layout drawing to include this option ;^)

I did have that thought Martin.
Personally I think it would perhaps be good to do a standard and a precision power supply now so there's a choice and it will make the drawings simpler too.


M

[norburybrook]

I'm back after a few days walking(and drinking) in Wales.

I've got rid of last weeks client this weekend so have a day free.

I unpacked the transformers today and they're huge. OT says maximum power 150w. minimum reproducible frequency @150w 27hz -3db

I think I've done the fiddly bit's now so I think I'm over the worst.

M

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[norburybrook]

Bit more work today. Realised I'd ordered 3.3R instead of 3.3k ...bugger no cathode resistors then...…

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M