Resistance Check

[Jimb0]

Hello. I just want to check if my resistances are OK. It is wired for 230v. I made some mods. I use 220uf 16v Nichicon FG instead of the 150uf cap. Also switched out resistors for Takman/Mills/Shinkoh and replaced stock caps with Clarity Cap 2.2uf 400Vdc

What is the reason for higher ohm at terminals where it should be 0?

2: 30Ω
3: 50Ω
4: 640Ω

12: 30Ω
13: 52Ω
14: 640Ω

A5: 250Ω
A6: 38Ω

B5: 104KΩ
B6: 104KΩ

22: 52Ω
23: 43Ω

25: 52Ω
26: 230Ω

31: 420Ω
32: 56Ω

35: 38Ω

 

[Jimb0]

More pics

 

[Jimb0]

Also is it ok to have terminals 21U and 23U bent like this? I missed the "this capacitor will lay flat on the chassis" part and clipped them before giving it enough lead to sit on the chassis

Also I apologize some pics are coming out backwards for some reason

 

[Paul Birkeland]

What value of resistors do you have installed between 1 and 6? and 11 and 16?  It looks like 22 ohms.  These should be 10K/5W.  Whatever you do, don't turn this on with this error.  I'm not sure what will burn up first, hopefully just the fuse, but things will be a bit unhappy in this configuration.

 

[Paul Birkeland]

Also is it ok to have terminals 21U and 23U bent like this? I missed the "this capacitor will lay flat on the chassis" part and clipped them before giving it enough lead to sit on the chassis

That's not particularly bothersome.  If you're shipping this overseas, you'll want to glue that cap down, glue the other power supply caps together so they can't move, and definitely provide some kind of external support to those Clarity Caps!

 

[Jimb0]

These are Mills 22 ohm 5W

That's not particularly bothersome.  If you're shipping this overseas, you'll want to glue that cap down, glue the other power supply caps together so they can't move, and definitely provide some kind of external support to those Clarity Caps!

Ok will do!

 

[FS]

I am sorry to get off topic here, but what sonic improvement do you expect from the 220uF Nichicon instead of the stock 150uF caps?
Thanks.
FS

 

[Jimb0]

Hi FS. I have not heard of this cap before, so I cannot comment on it. However, Greg Johnson from TNT mentioned he liked it more than other caps he tested, also inexpensive. My customer and I decided to try it with these upgraded components.

https://www.tnt-audio.com/ampli/bottlehead_moreplay_e.html

PB, is everything good to go with the preamp? What is the reason for the higher readings where it is suppose to be at 0 ohms?

 

[Paul Birkeland]

PB, is everything good to go with the preamp? What is the reason for the higher readings where it is suppose to be at 0 ohms?

I'm most concerned about the 22 ohm plate loading resistors...

Where are you connecting your black meter probe to measure the resistances?

 

[Jimb0]

I'm most concerned about the 22 ohm plate loading resistors...

Where are you connecting your black meter probe to measure the resistances?

Terminal 23

My apologies PB. I installed the wrong part. I mixed up the 22ohm 5W resistor with the 10K 5W when I was buying the parts.  :-[

 

[Paul Birkeland]

However, Greg Johnson from TNT mentioned he liked it more than other caps he tested, also inexpensive. My customer and I decided to try it with these upgraded components.

https://www.tnt-audio.com/ampli/bottlehead_moreplay_e.html

While we are always appreciative of reviews, there is some information posted in there I don't really agree with.

The cathode bypass cap handles the signal current rather than the cathode bias resistor at all but very low frequencies.  We provide a nice 1% Vishay CCF resistor there and I wouldn't recommend swapping that out, as something with a looser tolerance like a carbon film resistor may move the bias voltage around in undesirable ways.  The Nichicon UKA and UKW are (for now) their two highest tier electrolytic caps for audio.  For the purposes of being able to fill orders, we selected a cap that looked like it was generally available in large quantities, and with the discontinuation of many of the Nichicon audio grade caps, I'm glad we did. 

Using a 250V rated film cap with a surge to around 300V isn't a problem, though I wouldn't be as happy about doing that to a 250V electrolytic.  Looking at the datasheet for the typical cap we provide, it's rated to 375V for 1 minute, and typically (though not in this particular datasheet) there will be a specification that the cap needs to be run at or below its rated voltage for at least several minutes after being surged.  You'll see lots of old Counterpoint preamps from the 90s running 250V film bypass caps that see 400V every time you turn the preamp on, and they are still going strong.  When looking at the more expensive audio type film caps, the datasheets tend to be a little spare on application data, so YMMV. 

 

[Paul Birkeland]

Terminal 23

23 connects to 12 with a black wire.  12 connects to 2 with a black wire.  Having 30 ohms here means that there's possibly a soldering issue between 23 and 12, or you might want to double check what resistance reading you see if you touch your probes together, as that could be throwing things off a little.

 

[Jimb0]

Thank you very much for the help and important info PB. I will switch the cathode bias resistor back to the original one. You were right about the probes, I was using an alligator extension clip that increased the readings to 30 ohms. All the readings are back to 0 now.