Resistor Types

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crgfrench
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Re: Resistor Types

Postby crgfrench » Tue 08/13/19 11:15 pm

Without AC running through the resistor along with DC, there is no "resistor distortion". The whole idea of resistor distortion adding a second order harmonic requires that the resistor is in the audio signal path. And plate resistors are not in the audio signal path.
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Re: Resistor Types

Postby crgfrench » Wed 08/14/19 12:37 am

I just noticed that Danny Russell uses CCs in one spot only: the PI grid leaks. Hmm... Greta Van Fleet plays these.

Alice in Chains plays Meteopoulos, I feel like George isn't slinging "BS hype". He is a professional builder and amp tech. That said, I wouldn't use them in the input section where he indicates.

Who plays Keen's amps? I can't seem to find his builds anywhere.
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Re: Resistor Types

Postby Daviedawg » Wed 08/14/19 3:40 am

Gawsh. I missed all this while I was asleep.

A long long time ago I was told by a radio engineer who worked to keep all the BBC transmitters in Scotland on line and up to scratch (when they were valve receivers and transmitters) that every single thing in the circuit has an effect on the quality of the signal. He would know spending his working life fixing big hifi stuff with what was in the van as it were.

There are a lot of CCs in my 18 watt. I have no detectable noise from them. Whether they have a beneficial effect is totally subjective. But I like the look and I am happy with the tone I have. No science involved just lore.

They came by the bag load and I selected the closest values. But then I did have to swap out a couple when I had hiss soon after the build. So there is basis in the noise issue but it is not hard to resolve. And not all CCs cause problems. Except that in itself is a problem which commercial ampmakers have to consider. Whether you need or wish to bother is doubtful.

As a hobbyist I have time to take an empirical suck it and see what happens approach.

Dd
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Re: Resistor Types

Postby JMPGuitars » Wed 08/14/19 7:11 am

crgfrench wrote:
Wed 08/14/19 12:37 am
I just noticed that Danny Russell uses CCs in one spot only: the PI grid leaks. Hmm... Greta Van Fleet plays these.

Alice in Chains plays Meteopoulos, I feel like George isn't slinging "BS hype". He is a professional builder and amp tech. That said, I wouldn't use them in the input section where he indicates.

Who plays Keen's amps? I can't seem to find his builds anywhere.
This is a terrible argument. GVF is the worst thing to happen to rock and roll in at least 20 years. Their sound is TERRIBLE. If GVF played one of my amps, I'd be embarrassed. In case I'm being too vague here, I can't stand them. nono

Jerry Cantrell plays Friedman, Marshall, Fender, and Mesa. And even if he does happen to own one of those Metro amps (which I'd be a little surprised) it doesn't prove anything regarding the position of CC resistors.

I'm a pro builder and an amp tech. That doesn't mean I haven't bought into any hype. It doesn't mean he hasn't either. Maybe he believes the hype, that doesn't make it real. A good build quality of a good circuit with good components will sound good regardless of the resistor type...though metal film might sound too sterile. Or is that hype too? ;) I don't know, a lot of people use MF. Now I want to build an amp with mostly MF and see if I can tell the difference or not.

Here's Aiken's perspective, and certainly more on topic for this thread:
http://www.aikenamps.com/index.php/resi ... -it-matter
http://www.aikenamps.com/index.php/technical-q-a

Thanks,
Josh
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Re: Resistor Types

Postby crgfrench » Wed 08/14/19 7:44 am

Well, there you go. It's all subjective. That's why its art after all. Peace!
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Re: Resistor Types

Postby JMPGuitars » Wed 08/14/19 7:49 am

This is a good post on the topic:

https://music-electronics-forum.com/sho ... post304555

So much mojo in this subject matter, eh?
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Re: Resistor Types

Postby crgfrench » Wed 08/14/19 9:07 am

JMPGuitars wrote:
Wed 08/14/19 7:11 am
GVF is the worst thing to happen to rock and roll in at least 20 years. Their sound is TERRIBLE. If GVF played one of my amps, I'd be embarrassed.
I just couldnt help myself...
https://www.youtube.com/watch?v=w3XYb_SBWFo
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Re: Resistor Types

Postby JMPGuitars » Wed 08/14/19 9:30 am

crgfrench wrote:
Wed 08/14/19 9:07 am
I just couldnt help myself...
https://www.youtube.com/watch?v=w3XYb_SBWFo
🤮

Poor LedZep. Combining the lameness of GVF with Plant twirling his hair is...special?
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Re: Resistor Types

Postby AussieTim » Thu 08/15/19 5:13 am

Wow this has taken a turn for the weird which is OK with me, as the saying goes "when the going gets weird the weird turn pro!" and I can get as weird as anyone. Just ask my fishnet stockings
I think I have learnt what I have suspected and that is using carbon comp resistors is overrated and just like my analogy with tyres there are better modern types available. Lets face it we all love 57 Chevy,s but do you really want to lose your air-conditioning and sound systems with bluetooth, good fuel economy and comfy seats on your daily commute.
There seems to me to be a fine line between getting a good sound and hyperbole
I value all the inputs with this discussion and thank you all, i hope it will keep going and some more meaningful insights into resistors and their place in the soundscape of amps.
Long live Greta van Zeppelin, ill just keep listening to the old rock and roll and blues and drink whiskey {with pink lemonade told you I am weird}
Cheers
Tim
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Re: Resistor Types

Postby crgfrench » Thu 08/15/19 2:51 pm

JMPGuitars wrote:
Wed 08/14/19 7:11 am
Jerry Cantrell plays Friedman, Marshall, Fender, and Mesa
Its William not Jerry. William's signature head.
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Re: Resistor Types

Postby crgfrench » Thu 08/15/19 9:04 pm

JMPGuitars wrote:
Wed 08/14/19 7:11 am

Here's Aiken's perspective...
Highlight of Randall's conclusions:

"...it is better to use metal film for plate resistors."
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Re: Resistor Types

Postby JMPGuitars » Fri 08/16/19 6:37 am

crgfrench wrote:
Thu 08/15/19 9:04 pm
Highlight of Randall's conclusions:

"...it is better to use metal film for plate resistors."
Specifically he's talking about noise. The thing that's easiest to gather from his perspective there is that he leans towards HiFi with his component choices. I am going to build an amp with all metal film to see how it sounds because I'm curious whether or not it will sound sterile compared to carbon resistors. I'm also curious if it really will sound cleaner than the modern carbon films I normally use.
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Re: Resistor Types

Postby AussieTim » Fri 08/16/19 8:03 am

HI Josh I look forward to seeing your results
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Re: Resistor Types

Postby colossal » Fri 08/16/19 12:47 pm

I built a 100W three channel Plexi for a client once. This amp had metal film resistors and polypropylene signal capacitors throughout. The usual "formula" for a Marshall is carbon film resistors and polyester film foil signal caps. A mutual friend who I had built three Plexis for, swore this was one the finest "Marshalls" he had ever heard. He has no dog in the vintage part voodoo fight and wouldn't know carbon from metal film to look at or listen to. So he wasn't listening with his eyes or biased by preconceived, internet driven hearsay and so-called amp guru camp follower opinions. In my opinion, the amount of ignorance is superseded only by the sheer stupidity of some of the statements I read.

People often judge parts based on some divisive pedigree...either guitar amp or hi-fi, rather than looking at, understanding, and comparing the intrinsic properties such as dielectric, voltage handling, ESR/ESL, dissipation, etc. Hi Fi parts are often regarded by guitar amp people as some kind of cork sniffer exclusivity mostly because people cant justify the pricing. That's all well and good and there is certainly a marketing aspect to it which irks a lot of people, but that is beside the point.

A hi-fi part may be built to a higher degree of precision, and in small lots, which affects cost and supply. This doesn't make them inherently better or worse. Some people simply can't hear a difference in parts and therefore can't justify spending more than $0.03 for a Xicon carbon film.

Just some thoughts...not intended to inflame. These discussions often turn ugly and I don't know why. Use what you want. This is the art of building.
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Re: Resistor Types

Postby JMPGuitars » Fri 08/16/19 1:12 pm

colossal wrote:
Fri 08/16/19 12:47 pm
A hi-fi part may be built to a higher degree of precision, and in small lots, which affects cost and supply. This doesn't make them inherently better or worse. Some people simply can't hear a difference in parts and therefore can't justify spending more than $0.03 for a Xicon carbon film.
You're missing an important detail/part of the argument here. HiFi amps want to be clean and distortion free. Even a guitar amp's clean sound has some level of distortion, if it doesn't, it sounds terrible. If every component used in an amp is designed to reduce distortion, then you're potentially negatively affecting desired tone.

Regarding your MF amp build, the only way to determine that being the best build (for that reason), is to double-blind A/B test the same amp with both MF and other resistors. The difference in all the other components, and your skill level at the time of each build, all come in to play. You know all this though. ;)

This is an old (not-very-scientific) demo I did comparing capacitors: https://www.youtube.com/watch?v=kUDhBnMSuG0

I built all 3 amps at the same time, with all the same components, except for the tone/coupling caps. For that demo to be closer to scientific, I should have used the same amp build, and swapped the caps. I should have also used a prerecorded track on my looper pedal to make sure that the playing and levels were the same for each test. Obviously there are other factors too. But still, there's distinct characteristics that are more likely the caps, than the variance between transformer sets. To me, and most of the comments I received, the polyester caps were preferred. That doesn't mean that PP caps don't also sound great. A couple people did like the OD PP caps, but they were the least popular. Still sounded good, but not the best.
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