Resistor Choices

[tube-a-lou]

Hi all,
Had a bit of a noisy weekend with my Eico Hf-81 with a little static noise in the right channel.
It was a 100k resistor which I changed out including the one in the left as well. So my
question is I need a few more 100k's and been seeing a few Koa 100k's and Airco Speer's
as well are these decent resistors?, or any other choices it's for the preamp section so I don't
want metal film there.

 

[Drummerboy2]

Hi all,
Had a bit of a noisy weekend with my Eico Hf-81 with a little static noise in the right channel.
It was a 100k resistor which I changed out including the one in the left as well. So my
question is I need a few more 100k's and been seeing a few Koa 100k's and Airco Speer's
as well are these decent resistors?, or any other choices it's for the preamp section so I don't
want metal film there.

Do a search here, there are a lot of resistor info. Mills will work well.

 

[Drsnaut]

If Koa is the company that is also known as Kiwame, then these are fine resistors. Some people tend to over-use them, I wouldn't put them on every spot without thinking twice, but ok.
Takman carbon resistors are also nice if you don't want metal film. Resistors like Mills work pretty well in the power stage of your amp.

 

[CohibaJoe]

If Koa is the company that is also known as Kiwame, then these are fine resistors. Some people tend to over-use them, I wouldn't put them on every spot without thinking twice, but ok.
Takman carbon resistors are also nice if you don't want metal film. Resistors like Mills work pretty well in the power stage of your amp.

In there correct locations...These are my Top 5 choices.

 

[tube-a-lou]

I want to change a few 100k's in the preamp section, some of been in there since the amp's been put together
way back when. I did change the four 330K resistor's in the power section to metal film.

 

[Drsnaut]

Talking about favorite resistors; in the power section I really like mills/wellwyn. On the anode of smaller signal tubes I love the Amtrans resistors; on that position they blew me away (I once tried them as series resistor of my stepped attenuator and hated the sound!). Other favorites are Shinkoh (or any tantalum) and Vishay Z-foils.

Tube-a-lou, the position means a lot for which kind of resistor 'sounds' well (distorts less?). Do you have a schematic and allocated position of the resistor you want to exchange? That could help a lot.

 

[triode17]

Tube-A-Lou - It sounds like you are talking about the 100k plate feeds to V2 and V3. I don't believe in using fancy resistors for rebuilds. Metal film, carbon film, carbon comp. and metal oxides are all I need to do anything...quietly.
I have a studio mic pre. that uses 12AX7's and carbon film resistors that produced quite a bit of white noise when using high gains of about 55dB. Changed the plate resistors to metal film, 1% and the audible noise was gone. That's all I need to prove them out.
If you are indeed talking about V2 and V3, they are rather low gain circuits that IMO, could use almost any type of resistor to sound quiet again.
Why don't you want to use metal films?

 

[tube-a-lou]

It's in the Phase inverter section, tubes V3 and V8 there are four 100k resistors R27, R28, R56 and R57. I did put Metal Film in the output tube section R30, R32, R59 and R61 and you know it sounds a bit cleaner.

 

[Drsnaut]

Woah, thats not the nicest reading schematic around.
Correct me if I'm wrong but isn't r2 a balance pot? I assume you mean r27. I guess a takman carbon will do fine at r57&r28.
R56 and r27 an 2w Allen Bradley or Amtrans would be my pick...

 

[gadget73]

I don't believe in using fancy resistors for rebuilds. Metal film, carbon film, carbon comp. and metal oxides are all I need to do anything...quietly.

Glad I'm not the only one

Modern resistors are just way better than 50 year old carbon comp parts. Even fairly pedestrian mass quantity type stuff is a nice upgrade.

 

[tube-a-lou]

Woah, thats not the nicest reading schematic around.
Correct me if I'm wrong but isn't r2 a balance pot? I assume you mean r27. I guess a takman carbon will do fine at r57&r28.
R56 and r27 an 2w Allen Bradley or Amtrans would be my pick...

Oops I fixed that, that my great typing skills!

 

[Drsnaut]

Glad I'm not the only one

Modern resistors are just way better than 50 year old carbon comp parts. Even fairly pedestrian mass quantity type stuff is a nice upgrade.

True. Although I believe the Takmans and Kiwame's are quite affordable. Replacing resistors ain't gonna cost the world anyways; why not add that extra 60 cent?

 

[gadget73]

I buy parts by the 100 usually, so its a lot more than 60 cents For something special I have gotten high accuracy parts, but for general work I usually just use the boring stuff. The Fisher RIAA network I rebuilt got Vishay Dale 1% parts.

 

[Pioneer.user]

Hi

Can someone help me identify these resistors? All I know is that it's carbon resistors with brass cap. I did research and I know that Amtrans carbon resistors also has brass cap. Bu it's all that I know.
Thanks

 

[Dandy]

I think what you are calling the 'brass cap' is the gold band that indicates high (5%) tolerance. Silver indicates 10%.

 

[Pioneer.user]

I think what you are calling the 'brass cap' is the gold band that indicates high (5%) tolerance. Silver indicates 10%.

I'm talking about brass cap like on this photo