Resistors & Capacitors & Diodes, Oh My!

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MadAsAHatter

MadAsAHatter

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I’m getting ready to start sourcing components for my Hilbish GT120 (Matamp GT120 Clone) build. This is the first build where I’m sourcing all the parts instead of buying as a kit. I have the BoM so I know what I need as far as values of everything goes. I can also read color codes and whatnot. What I need help with is the appropriate type of capacitors, resistors, diodes, etc.

Outside of the BoM saying do not use ceramic capacitors, there’s no other specifications on which types of components. I’ve been reading everything I can on the subject. I understand the general idea that different composition of materials will have their advantages/disadvantages, but I don’t know which ones are more appropriate for tube amps. For instance CC vs metal oxide resistors. Is one “better” than another? Can any be used and it’s more about tolerances and price? Same questions about capacitors, diodes, etc. Which ones to use. I hear/see talk about mustard caps and orange drop caps. Is this a branding thing or just a reference to their color and shape?

While on this subject, what about wire? I see there’s a couple of different options here as well. Is there any preferred type of wire to use? I’m not going for vintage accuracy or anything. I just want to make sure I’m getting the appropriate type so it doesn’t burn out under working voltages.
 
MadAsAHatter said:
I’m getting ready to start sourcing components for my Hilbish GT120 (Matamp GT120 Clone) build. This is the first build where I’m sourcing all the parts instead of buying as a kit. I have the BoM so I know what I need as far as values of everything goes. I can also read color codes and whatnot. What I need help with is the appropriate type of capacitors, resistors, diodes, etc.

Outside of the BoM saying do not use ceramic capacitors, there’s no other specifications on which types of components. I’ve been reading everything I can on the subject. I understand the general idea that different composition of materials will have their advantages/disadvantages, but I don’t know which ones are more appropriate for tube amps. For instance CC vs metal oxide resistors. Is one “better” than another? Can any be used and it’s more about tolerances and price? Same questions about capacitors, diodes, etc. Which ones to use. I hear/see talk about mustard caps and orange drop caps. Is this a branding thing or just a reference to their color and shape?

While on this subject, what about wire? I see there’s a couple of different options here as well. Is there any preferred type of wire to use? I’m not going for vintage accuracy or anything. I just want to make sure I’m getting the appropriate type so it doesn’t burn out under working voltages.
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Check out the Valvestorm site.. they're going to have pretty much everything you need.

Also.. Antique Electronics Supply.
 
Personally I go to Mouser for most everything. I use nichicon for electrolytic caps. 1 watt metal film resistors with 1% tolerance for most resistors except where 2w or 3w. Film caps are a whole different ballgame. I like panasonic and orange drop 615 and 715 series, wima. Actually, I'm pretty much good with any cap it's just a matter of cost and foot print. I just did a 2204 build with Sozo's but honestly I didn't feel they were any better or worse than similar lower priced options. Weird they said no ceramic though. I would choose that over silver mica. I have a populated pcb for the GT120 and a set of heybooer transformers before completely deciding to try the slo build instead.
 
griff10672 said:
Oh man ...... you talk about rabbit holes .....
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Tell me about it... I'm still trying to decide which green magic marker makes my MP3's sound best. Right now I'm stalking a production batch from 1898 to see if they sound better than the 1903 batch, which has a great sound stage but is a bit cloudy in the high-end and not 3D enough.
 
MadAsAHatter said:
For instance CC vs metal oxide resistors. Is one “better” than another? Can any be used and it’s more about tolerances and price?
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My understanding of this particular issue is that carbon comps are bad from a reliability standpoint, both because of drift in value and because they can go out in a fiery blaze of glory if overpowered.
 
Generally metal oxide film > metal film > carbon, but can also depend on values needed and reliability/heat proximity needs. This all would honestly require pages of a response, so just send a list of what you need and I'll save you some time and $$$, maah. I have a lot of this stuff.
 
MadAsAHatter said:
While on this subject, what about wire? I see there’s a couple of different options here as well. Is there any preferred type of wire to use? I’m not going for vintage accuracy or anything. I just want to make sure I’m getting the appropriate type so it doesn’t burn out under working voltages
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get the stuff with Teflon in the coating ....... I swear you can put that stuff on the surface of the sun and it won't melt ....
 
NowYou'rePlayingWithPower said:
100% But like Griff said; welcome to wonderland.
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Fair enough. Now really, I must be going...
1706059421222.png
 
Buy from everyone.. You think you have everything, but then you don't.

Ola did a 2C video and commented on how much noisier the original one was which has CC and CF resistors..
 
midnightlaundry said:
Buy from everyone.. You think you have everything, but then you don't.

Ola did a 2C video and commented on how much noisier the original one was which has CC and CF resistors..
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Carbon composite resistors generally have worse tolerance/accuracy to "on paper" specs. Depending on how cheap someone wants to go they could be off as much as 20% or more, so each one would have to be measured individually. You could go e24 and get them closer to 5% tolerance, but I say skip them all together.
 
NowYou'rePlayingWithPower said:
Carbon composite resistors generally have worse tolerance/accuracy to "on paper" specs. Depending on how cheap someone wants to go they could be off as much as 20% or more, so each one would have to be measured individually. You could go e24 and get them closer to 5% tolerance, but I say skip them all together.
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To add to this, I have a bunch of older ones that have drifted like crazy. I think at least one was around twice the marked resistance? Anyhow, another vote for skipping carbon comps.
 
ClintN667 said:
Personally I go to Mouser for most everything. I use nichicon for electrolytic caps. 1 watt metal film resistors with 1% tolerance for most resistors except where 2w or 3w. Film caps are a whole different ballgame. I like panasonic and orange drop 615 and 715 series, wima. Actually, I'm pretty much good with any cap it's just a matter of cost and foot print. I just did a 2204 build with Sozo's but honestly I didn't feel they were any better or worse than similar lower priced options. Weird they said no ceramic though. I would choose that over silver mica. I have a populated pcb for the GT120 and a set of heybooer transformers before completely deciding to try the slo build instead.
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Mouser is where I started shopping first. They have so much available it can get a bit overwhelming not knowing exactly what I'm looking for.
I'm not sure the reason for no ceramic caps. I can only assume it either doesn't work right or not accurate to the original circuit; IDK? This is up at the top with the general notes.

1706083559220.png
 
griff10672 said:
Oh man ...... you talk about rabbit holes .....
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I'm sure it's a deep, deep well when you get into fine tuning the sound. I'm just at the point of making sure I use the appropriate type of components so all works how it should. Well down the road when feel like I have a better grasp on the finer details I can take a dive into that rabbit hole.
 
7704A said:
My understanding of this particular issue is that carbon comps are bad from a reliability standpoint, both because of drift in value and because they can go out in a fiery blaze of glory if overpowered.
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NowYou'rePlayingWithPower said:
Carbon composite resistors generally have worse tolerance/accuracy to "on paper" specs. Depending on how cheap someone wants to go they could be off as much as 20% or more, so each one would have to be measured individually. You could go e24 and get them closer to 5% tolerance, but I say skip them all together.
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So at least in a broad sense carbon composite seem to be at the bottom of the barrel?
 
Random thoughts:

For most of the resistors you need to choose between carbon comp, carbon film, or metal film. Marshalls used carbon film so many people just use the cheap Xicon carbon film you see everywhere (the tan colored ones). The plate resistors are probably the most sensitive, using carbon comp there often results in excess hiss and noise. So some people might use metal film for the plate resistors, especially V1 since everything gets amplified from there. These are usually 1/2w but some use 1w here and there. I like the Beyschlag metal films for plates.

Metal oxide for the power supply work fine. These are usually 2w, 3w or even more. The little red ones from AES are good, cheap, and small.

Use flameproof for the screen grids, wire wound ‘sandbox’ type or metal oxide work.

The Vishay polyester film caps are good quality 630v caps. Mallory 150 are good too. You can spend extra for Synergy Royal Mustards or Jupiter et al but you probably won’t hear a difference. Nothing wrong with orange drops, I always use polyester ODs if using them and not polypropylene but I doubt these old ears could hear a difference. Polyester film are what Ken Fisher used so there you go. NOS caps have gotten really expensive and harder to find.

Nothing wrong with spending a little extra for these parts. It only hurts once and it’s not big money. You might not hear a difference but it still looks cool. I think that matters when building custom one offs. But you also might be surprised to see some custom 5k amps using cheap Xicons and Mallory’s…and sound great.

There are also some strategic spots where the ‘noise’ or ‘distortion’ that may come from Carbon Comp resistors is wanted, ie it could sweeten the tone but not add noise/hiss. All debatable whether you could hear it but the tone stack slope and NFB resistors are two spots you might see a random carbon comp resistor. Also the PI plates sometimes. I’ve done it several times just as a matter of course.
 
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I am currently in this rabbit hole with my 2203 clone and here is how I went with it. First, every component makes a difference. Some more, others less. Changing one cap or one resistor is not going to make much of a difference, but changing a couple of them in crucial spots will make differences in EQ, break-up characteristics and response/feel.

I made myself some "components holders" out of 22awg solid wire (see pic). Use one piece of wire and wrap it around another piece and than cut in shape. I soldered them to my turret board and was able to quickly test different cap brands and resistor materials on the fly. Just make sure, that every time you change anything, unplug the powercord of your amp and DRAIN YOUR FILTER CAPS!!!

Some findings:
There is no "don`t use this or that cap". Ceramic caps bring out the "krrr" and grind, that Marshalls are known for compared to silvermicas. Silver micas remove some of the highend fizz, but still come off as bright due to their lack of bass. But they track slower as ceramics.

OD 715 produce rather bright harmonics. They have a fast tracking bass, that is firm, but still goes deep. However, the highend gets glassy and sterile. Sozos have a more "wobbling", dark bass but still track fast.

CCs fatten or soup up the tone in the mids and lower mids department. They add second order harmonics as they tend to distort the signal lightly. But here is the problem with CCs, they removed all the push from the amp. No fast tracking, no push and no responsiveness of the bottom end like you would expect from a Marshall. It`s like you are fighting the amp.
You will hear the effect of CCs most were there is a big voltage drop across the resistor, like the anodes of the preamp tubes.

For wires, on the metro amp forum most people settled for teflon insulated, silver plated Mil spec wires.
 

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MadAsAHatter said:
So at least in a broad sense carbon composite seem to be at the bottom of the barrel?
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Yes and no.

v v v This v v v
SpiderWars said:
There are also some strategic spots where the ‘noise’ or ‘distortion’ that may come from Carbon Comp resistors is wanted, ie it could sweeten the tone but not add noise/hiss. All debatable whether you could hear it but the tone stack slope and NFB resistors are two spots you might see a random carbon comp resistor. Also the PI plates sometimes. I’ve done it several times just as a matter of course.
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v v v v Also, this v v v
7704A said:
To add to this, I have a bunch of older ones that have drifted like crazy. I think at least one was around twice the marked resistance?
Click to expand...
 
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