buying resistors

[menger66]

I need to resupply my resistors so far ive checked out allied, I was thinking id buy the ohmite 1watt CF, they seem reasonable priced, anybody use these and what do you think? what other sources should i check out befor ordering the ohmite from allied? mark

[renshen1957]

I need to resupply my resistors so far ive checked out allied, I was thinking id buy the ohmite 1watt CF, they seem reasonable priced, anybody use these and what do you think? what other sources should i check out befor ordering the ohmite from allied? mark

Hi,

There are also many good brands from the consumer goods level (future land fill electronics) to audiophile expensive.

Allied has some good choices, http://www.alliedelec.com/passive-compo ... 4294965083
are RCD resistors, and of good quality.

You might check out mouser.com which is generally less expensive than alliedelec.com for most of its components and has better variety. However, they do not stock Ohmite in the 1 W.

There are also many good brands from a variety of other electronic stores online to specialist companies.

Warning: Mousers website is not intuitive, and the search function leaves a little to be desired.

Some builders use Xicon (translation Mouser's sourced in Asia house brand) and claim these work fine and are cheap for the 1/4W and 1/2 W, line. The Xicon 1 W CF cost individually more than other 1 W I have seen (and usually the Xicon brand is less expensive in general). Mouser wanted $0.30 USD for 1 W Carbon Film Xicons. Usually individual resistor at lower values are under a dime. The 2W Xicon (100k) value is $0.22!

Mouser carries the 2 W KOA SPR2 sold at greater expense as Kiwame (see partsconnexion.com below).

I found these to be among the best Carbon Film I have tested as to low noise for Carbon Film. The lead diameters are larger so with eyelet cards with a bunch of resistors in a particular eyelet, it may be a problem (unless you plan ahead and use a larger eyelet) when making your own circuit cards or you may need to modify a pre-assembled card sold separately or with some kits.

The marketing (Kiwame, see http://www.diyaudio.gr/kiwame.htm quoted below) claims lower thermal noise compared to Metal Film (Not to open a can of worms.) Suffice to say I found these to be very quiet, and have tin-plated copper leads (not copper over steel), usually a sign of quality.

("Kiwame resistors are made of carbon film and their case is actually the first one for use is audio applications with superior specifications.

(KOA SPR2 and SPR5 are sold as Carbon Film Power resistor).

Considerably low thermal noise levels, lower than metal film resistors.

Lower distortion artifacts

On the other hand they offer true 0.5% tolerance despite their nominal E24-series 5% label.

The outer layer that surrounds the conducting carbon film is a (flame proof) silicon(e) compound.

The maximum operating voltage is very high; some 500Volts for the 2W package and 600 Volts for the 5W package. In addition they can withstand voltage surges up to 1000V (2W) or 1200V (5W).

(Exclamation points removed)" Take what they say with a grain of salt, but I found them excellent and quiet.)

I purchased a sample of the higher (Kiwame, 1%) and lower tolerance (2 W KOA SPR2 5%) and found them to be spot on the same when tested with a multimeter in some cases (with better test equipment) within 0.4% of the value. I have tested 100K resistors under either name which were spot on 100k, 99.9k, and 99.7K You have to love the Japanese for quality control.

www.partsconnexion.com has a variety of audiophile carbon film. Amtrans (black anodized aluminum case, epoxy filled, copper-plated brass end caps, gold-plated OFHC leads) at $4.50 (3/4W) to $USD $6.50 USD (2W) a pop to replace the no longer in production Riken), Kiwame ($1.10 each compared to KOA SPR2 $0.44) , NOS Riken ($4.95 1 W if you can find the values), Takman Rex (1W, $1.40 UDS).

You don't have to spend a fortune on resistors.

I spend the extra $0.14 and purchase the KOA SPR2's from mouser instead of mouser's Xicon magnetic made in Thailand resistor (at least this is on the plastic bag country of origin from mouser). Or I use RCD, ; little rebel from Ohmite is less money at $0.19.

www.justradios.com has a good selection of tube radio repair resisters (rated for higher voltage) that is new stock and reasonable. They carry 1W CF from 680k-20M and 2W CF from 330K to 22M

The 2 watt CFQ2 by Stackpole (the regular CF series sometimes is copper coated steel leads) has tinned copper leads, a 500v maximum working voltage, 1k volt max pulse, would work for plate load and power supplies. These run $0.20 USD at Handmade electronics. As good a quality as the Ohmite little rebel 1 watt resistors and the same price as mouser (I haven't check Allied)

Handmade electronics caters to the DIY Hi-Fi crowd, but is less expensive (and with less variety) than Partsconnexion.

The above are all North American firms. Let me know if you are in Europe, Asia, etc.

Just some suggestions. I am sure others will chime in. You will find a variety of opinions on carbon film resistors.

Best regards,

Steve

[Jack Hester]

I need to resupply my resistors so far ive checked out allied, I was thinking id buy the ohmite 1watt CF, they seem reasonable priced, anybody use these and what do you think? what other sources should i check out befor ordering the ohmite from allied? mark

Any particular reason for the Carbon Film? I just recently posed a similar question over on the Hoffman Amp site, and metal film seems to be a preferred type, for it's quietness.

I have an abundance of Carbon Comp, for old amp repairs. And, have used them for some scratch-built experiments, as proving out a design was the main interest.

But as I'm trying to organize a bit better, and standardize with good quality components, I'm tending towards the metal film. I'll continue to use my CC for repairs, when needing like in kind for such. Everything else, I'll order the metal film.

A good friend of mine told me the same thing today at Church. He buys only metal film for his builds.

Anyway, giving you another choice, and an opiinion.

Jack

[renshen1957]

I need to resupply my resistors so far ive checked out allied, I was thinking id buy the ohmite 1watt CF, they seem reasonable priced, anybody use these and what do you think? what other sources should i check out befor ordering the ohmite from allied? mark

Any particular reason for the Carbon Film? I just recently posed a similar question over on the Hoffman Amp site, and metal film seems to be a preferred type, for it's quietness.

I have an abundance of Carbon Comp, for old amp repairs. And, have used them for some scratch-built experiments, as proving out a design was the main interest.

But as I'm trying to organize a bit better, and standardize with good quality
components, I'm tending towards the metal film. I'll continue to use my CC for repairs, when needing like in kind for such. Everything else, I'll order the metal film.

A good friend of mine told me the same thing today at Church. He buys only metal film for his builds.

Anyway, giving you another choice, and an opiinion.


Jack

Hello Jack,

I could ask the same question of metal film, why metal film?

Yes it's quieter, however no vintage amp used metal film.
To many an ear, the sound of metal film circuits have been described as cold, sterile, analytical, and other such adjectives.

Some professional builders use carbon film to recapture the warmth of a vintage amp without the noise of carbon comp resistors; in reaction to all metal film amps. And other builders and the big boys use metal film in their reissues, the former with great results and the later with fair to mediocre results.

I use a variety of resistors in an amp build. I use specific types in specific areas. I shy away from the mf resistors as the exclusive resistors in the signal path, but I do use the high quality PRP metal films as cathode resistors in the preamp. These I have found to be better than the run of the mill Xicon MFs.

Another builder I know uses MFs through the Signal path, but uses an audiophile carbon film as the first grid leak in the preamp to give a little warmth and vintage tonality to the amp, and he custom builds hi-fis.

What's the big deal about quietness. Any number of amps will have more than one FX pedal which are noisier than any carbon comp resistor or through multiple stompboxes without true bypasses. Or they eventually resort to a.noise gate.i

I recognize the value of quiet in a recording amp, but that has more to do with proper grounds, lead dress, mains power supply filtering, extra.

Considering how many classic records were cut using not so quiet amps (jazz, country, as well as blues, and rock) with analog recording equipment, playback amplification, etc it's a wonderful these ever sold because people used cc resistors in most of the equipment.

Of course, I am joking, but a number of musicians tour with vintage amps, some with cc or cf resistors and no one seems to complain.

The Ultimate Experience re-issues cut of Red House has Jimi's reply to a band member's comment about the cc resistors noise is interesting as the frying fish sound disappeared with the first note and wasn't heard subsequently.

Clark Amps amd Victoria built all CC amps and didn't seem to have a shortage of buyers for their wares, new or used.

Then again I would not build a Dumble Clone without MF resistors on the Plates and CF elsewhere.

I see nothing with using cf resistors, or metal film. That's another side of the coin.

Best regards,

Steve

PS Hooray for carbon comps.

[Jack Hester]

I see nothing with using cf resistors, or metal film. That's another side of the coin.

Best regards,

Steve

PS Hooray for carbon comps.

Steve -

Good argument for both. I, too, will continue to use my CC on any of the old amps that I have a fondness for resurrecting. When I posed the question over on the other site, I noted that my B-12-N was my standard for quiet. Meaning no hiss or hum with the volume(s) at full. I know that I can't make them all like this. I don't try to. But, I strive for it and accept what I get. It, by the way, doesn't have any CC resistors in the amp, though they are in the PS.

So, I suppose that it's a matter of application. Still a good argument for either.

Jack

[Structo]

Great points gentlemen.

Steve nice write up on the various CF resistors.

[renshen1957]

I see nothing with using cf resistors, or metal film. That's another side of the coin.

Best regards,

Steve

PS Hooray for carbon comps.

Steve -

Good argument for both. I, too, will continue to use my CC on any of the old amps that I have a fondness for resurrecting. When I posed the question over on the other site, I noted that my B-12-N was my standard for quiet. Meaning no hiss or hum with the volume(s) at full. I know that I can't make them all like this. I don't try to. But, I strive for it and accept what I get. It, by the way, doesn't have any CC resistors in the amp, though they are in the PS.

So, I suppose that it's a matter of application. Still a good argument for either.

Jack

Hi Jack,

The author I respect the most on tube amps for MI uses MF resistors exclusively. He is very much against voodoo parts. And I agree to a point to where my experience differs. He prefers to use modern parts to make amps. That's his opinion, we are building older circuits but no reason not to use better materials which won't drift or become noisy with time.

From a view of reliability, it depends on the use. Metal Film resistors aren't used in defibrillators, they do not have the surge or over voltage qualities of carbon comp. Metal film are not used in 20 megaohm or higher RF. MF resistors failures were reported in 1992 from residual chlorine used by one manufacturer to clean components that did not occur with the old (cc) resistors in computer monitor early life test. The failures were from upward drift. This was a contamination problem that was solved.

Of course we aren't discussing medical or rf broadcasting. However one of the major reasons guitar amps aren't made with cc resistors is price. The carbon film resistors saw the light of day in the 1930's. The cc was used and manufactured in bulk so was still the choice. Fender used 1/2w cc resistors for cathodes instead of 1/4with cc's as the latter were more expensive at the time.

RCD in their online catalog writes carbon comp resistors as being the most reliable of resistors. CC are not considered obsolete, a surface mounted MELF variety exist (same can be said of other resistors).

It is hard to say what today's mf resistors condition will be in 50 or 60 years in a Guitar amp. The Fender amps of recent vintage don't have the longevity that their older brethren had but that has to do with design economy, choice of correct wattage but smaller part size and from other cost cutting design decisions for a price to match a segment.

Had Fender, Gibson et al had followed the European practice of Tubes right side up, so the heat of the tubes didn't bake the circuitry, maybe the cc resistors would be held in higher esteem, aside from noise or in use in precision test instruments or high moisture environments.

My son's vintage 5E5-A (with octal preamp tube) is untouched other than the filter caps, the amp is quiet as any modern Fender if not quieter. My The Fisher profesional series integrated from the 1960's was noisy when I acquired the amp. After cleaning the pots and re tubing with NOS tubes what I thought was cc thermal noise disappeared and it's as quiet as a grave. I don't know if metal films will last as long, but mf resistors are fireproof for the most part and added advantage.

Best regards

Steve

PS

Kevin O'Connor is the author I hold in high esteem.

He makes a very good argument for using film capacitors instead of electrolytic caps in the power supply for longevity (the film caps should last the life amp). He also uses polypropylene resistors in the signal path, which I don't, nor do I want to hijack the thread. But as he points out, some of the distortion from the electrolytic caps are part of the classic amp sound. So there are some pot holes in using modern parts and applications.

He has other methods of achieving that tone, as his amps aren't one trick ponies (he does not build versions of vintage amps) and very versatile this is not a concern. His company is London Power.

[Jack Hester]

Steve -

Though it's not my thread, I wouldn't think that it would be considered a hijack. It's a very good discussion. Though looking back now, I can see that Mark was really wanting an opinion for CF sources. So, I probably was the original hijacker. I'll refrain from any but discussions of sources. I'm still glad that you said what you did.

Jack

[gui_tarzan]

I've been getting all my resistors and a few other parts from Digikey. Great & quick service, and from what I've seen so far good prices.

[Ken Moon]

I like resistors that print the values rather than using color code bands (it's a bitch getting old).

The previously mentioned KOA/Speer 2W resistors (the green ones) have this feature:

[img:450:365]http://www.partsconnexion.com/media/pro ... /kiw5W.jpg[/img]

For wirewound power resistors, I love the Mills MRA-5 (5 watt) and MRA-12 (12 watt) lines:

[img:450:347]http://www.partsconnexion.com/media/pro ... s/mra5.JPG[/img]
[img:450:322]http://www.partsconnexion.com/media/pro ... /mra12.JPG[/img]

In the 3-watt MF category, I used the IRC GS-3 line, but they seem to have been recently discontinued

[img:500:400]http://www.tedss.com/stock/images/2021/2021007800.jpg[/img]

I must admit that as hard as I've tried, I can't seem to hear much tonal difference between resistors. If I want a change in tone, I need to change the speaker

[dcribbs1412]

In the 3-watt MF category, I used the IRC GS-3 line, but they seem to have been recently discontinued

Hey Ken
are these the ones you are talking about?
http://www.mouser.com/ProductDetail/IRC ... kT5adKM%3d
Mouser seems to have a few values in stock
I like these also

Darin

[Ken Moon]

Hey Ken
are these the ones you are talking about?
http://www.mouser.com/ProductDetail/IRC ... kT5adKM%3d
Mouser seems to have a few values in stock
I like these also

Darin

Yep.

Great for plate resistors.

[TUBEDUDE]

Are those Mills resistors non-inductive?

[jaysg]

I've got a happy camper customer after installing some RN65 resistors in plate positions on a couple modern Fenders, like the DeVille. It takes care of what I hear as an unpleasant graininess in the clean tone.

[Ken Moon]

Are those Mills resistors non-inductive?

Yes - here is the datsheet

http://www.vishay.com/docs/31801/mra.pdf