5e3 Dialing In The Years? Carbon Comp vs. Metal Film, Jupiter vs. 150 etc

[DougGuy]

I read the phrase "dialing in the years" which referred to using vintage style components in certain places, and modern components elsewhere so my question would be in the 5e3 type amp, given the choices of traditional carbon comp, carbon film, and metal film resistors, where would you place each type if you wanted to keep the classic/vintage tweed tone but reduce the noise floor and tighten up the bottom end a bit where possible?

Same question applies to tone caps, I can choose between the 150s, Mojo dijon, and Jupiters, so what would you choose and at what position in the circuit?  Also since this is a 5g9 Tremolux, which caps would you choose for the tremolo array?

I read one post that the builder had swapped in a full compliment of Jupiters and said save the money he couldn't tell enough of a difference to warrant the cost, and he may be right but what speaker did he have, what guitar what pickups?  It would seem to me that the situation he tested under might not have been the best comparison for swapping tone caps if he heard no or very little difference. 

[Latole]

When building an amp:
I'm not trying has to know which resistor is preferable to such place rather than to another.
I know that technically some are to be preferred to others.

Capacitors; oranges drop. I have never tried Jupiter and other high end products.
Filters; F&T and Sprague.

When I repair an amp, I put the same type of resistor.

[HotBluePlates]

... in the 5e3 type amp, given the choices of ...

My first amp build ~20 years ago was a 5E3 Deluxe.  I was all excited, and tried to pick "the best of everything."  It sounded like a tweed Deluxe.

If you use carbon comp, carbon film, metal film, or wirewound resistors, the amp will sound substantially the same.  So pick whatever makes you feel good.

... Same question applies to tone caps, I can choose between the 150s, Mojo dijon, and Jupiters, so what would you choose ...

All 3 cap types you mentioned are polyester dielectric.  If "different caps" could sound different, those choices won't sound different-enough to matter.

I wasn't always sure of that, so I built a cap-substitution box to hear the difference between 12 different cap-types right now.  Polyester up to Teflon.

I tried the box in place of a cap in that tweed Deluxe build; no difference for all 12 caps.  But switching from 0.1µF to 0.047µF to 0.022µF made a very-obvious difference.

These days I usually pick an inexpensive polyester cap for most chores in an amp.

[DougGuy]

My first amp build ~20 years ago was a 5E3 Deluxe.  I was all excited, and tried to pick "the best of everything."  It sounded like a tweed Deluxe.

If you use carbon comp, carbon film, metal film, or wirewound resistors, the amp will sound substantially the same.  So pick whatever makes you feel good.

I tried the box in place of a cap in that tweed Deluxe build; no difference for all 12 caps.  But switching from 0.1µF to 0.047µF to 0.022µF made a very-obvious difference.

Thank you that's exactly the kind of information I was looking for.

[Latole]

Fews years ago I try different caps for tone in a '52 RI Telecaster.
Caps are with same values and I use multi-switch for A/B test.
I can hear very very little difference on one cap. I solder this one in my Tele.

Nothing to convince me to do the same for an amp to follow my first answer

[jjasilli]

One of the published amp guru's suggests that to duplicate vintage tone, use carbon comp R's in critical places, like tube grids & plates.  In a simple amp, I guess that's everywhere.  Anyway, I think there's no pat answer to this question.  Do what hotblue did, and A/B for your own ears.  A problem is that tonal perception is very subjective; subject to confirmation bias; and can change at different listening sessions.


E.g., some years ago, "stacking" caps in the signal path was all the rage.  I.e., using 2 caps of different types in parallel to get the total desired C value.  The theory is that paper & oil caps pass bass better than plastic caps, which pass hi's better.  I think this was a passing fad.

[Mike_J]

I am rebuilding my 5f6a Fender Bassman clone. When I first made it 22 years ago used Allen Bradley carbon comp resistors same as Fender did. In the rebuild nothing but metal film. Why because they are much quieter and I don't see any or certainly enough tone difference to justify the noise. Keep in mind I have enough of the AB CCs to make many tweed Bassman or Deluxe amps. Use them now if I need a nice lead. Their leads are substantial.


Did the same when I made my 5E3 as far as metal films are concerned. Quiet amp and since I modified the cap and resistor on V1-8 it is a very enjoyable amp to play.


One thing you need to consider is what board are you going to use. If it is one of Doug's, which are excellently designed, then you should use either 150s or Xicon either polyester or polypropylene. Try each and see if you see a difference worth the time. Doug's boards are designed for one of those caps. Larger caps like the Jupiter's probably wouldn't fit well. I made a two-channel AB763 amp with nothing but 150s and it sounds great. Could be the hard maple cabinet has a little to do with it.

[pdf64]

One of the published amp guru's suggests that to duplicate vintage tone, use carbon comp R's in critical places, like tube grids & plates...

May be thinking of RG Keen’s page on the topic http://www.geofex.com/Article_Folders/carbon_comp/carboncomp.htm
So that’s CC for later stage preamp anode loads, ie where there’s large VDC & large signal VAC across them.
Nowhere else, definitely not early stage grid circuits

Contrary to RG’s advice, the signal I measure at an input stage anode can be pretty large.
And (even MF) 68k input resistors are still the most significant noise source in a regular amp.
Of course an MF is way quieter than a bad CC anode load. But then a good CC is too 
So for my own stuff I use CC for all preamp anode loads, just for the mojo factor, not because I’ve noticed a difference 
None I’ve fitted have gone noisy, even decades later, if they do it’s not a problem to replace them.

For repairs though I use MF or MO, as appropriate.

[Bieworm]

Imho one can benefit more from determining the foil side of the caps and thus orientate them right. I use vishay caps most of the time. Good quality fir a reasonable price.
I use MF and MO resistors all over and always pleased with sound or noise.

[66Strat]

I like metal film resistors and orange drop 418p capacitors. The orange drops look great against a black circuit board. Now I just need to find a supplier for chrome capacitors and loud pipes to complete the HD theme.

[DougGuy]

Fews years ago I try different caps for tone in a '52 RI Telecaster.
Caps are with same values and I use multi-switch for A/B test.
I can hear very very little difference on one cap. I solder this one in my Tele.

Nothing to convince me to do the same for an amp to follow my first answer

I solder in two clip leads to the tone pot in the telecaster, and I dump out my bag of PIO caps and I clip them in one by one until I get one that says ME ME ME ME ME!!!!!!  And I use that one.  There are differences because of drift, and there are also differences because of materials used. 

Anybody that says a .022uf cap is going to sound the same regardless of make or age is just not being realistic.  There are audible differences.  Guitar is a dynamic load on an amp, and a lot of things affect how the tone pot will operate, not just the value of a cap.  It is more the sum of the parts including the speakers in the amp than it is picking a cap at random and soldering it in and never looking beyond that to compare what other caps may sound like.

I have a Fulltone Deja Vibe pedal, I plug it into the Marshall it sounds oh so so, nothing special, does what it is supposed to.  Plug the same pedal into the Dr. Z oh holy moly what a cool spatial 3-D effect it gives the sound!  You aren't really aware there is a deja vibe there, on a slow sweep, it just has this texture that comes out into the room and takes on a life of it's own.  Go figure!

[thetragichero]

not to start an argument, but different guitar tone caps of the exact same value sounding different is a bunch of hogwash/confirmation bias/psychoacoustics at work. great marketing but besides looking cooler, those $100+ wiring harnesses with bumblebee caps sound no different (all values being equal) than a ceramic or chiclet caps. tone cap doesn't even come into play until the very end of the tone pot's travel (before then the decrease in treble is due more to the pot's decrease loading on the pickup than anything else). granted, the customer gets what the customer wants (and is willing to pay for) but there ain't no difference besides price and a fluffy sales pitch (reminds me of a time a decade or so ago when even folks like callaham, who make a darn fine bridge, were running absolutely EVERYTHING through cryogenic treatments at a healthy upcharge)

[pdf64]

Tinnitus and hearing loss kinda excuse me from subtle ’can you hear the difference’ tests.
But nonetheless, I’m intrigued what resistance is the tone control set to when undertaking guitar tone cap comparisons?

[pdf64]

...Anybody that says a .022uf cap is going to sound the same regardless of make or age is just not being realistic.  There are audible differences...

See link below, I'm not aware that there's anything factual to back your claim. Consider the human factor, eg unconscious bias may cause difference to be perceived where none exist.

...Guitar is a dynamic load on an amp...

I can't see how that could be? Rather the speaker is a dynamic load, ie it is a load, and its characteristics change a little according to signal level, hence dynamic. The guitar is the signal input to the amp.

...a lot of things affect how the tone pot will operate, not just the value of a cap...

Indeed but I'm not aware of how cap type (film and class 1 ceramic) per se can be included in that?

...I solder in two clip leads to the tone pot in the telecaster, and I dump out my bag of PIO caps and I clip them in one by one until I get one that says ME ME ME ME ME!!!!!!  And I use that one.  There are differences because of drift, and there are also differences because of materials used...

Consider that some of the caps in your bag may be failing, hence an audible difference; whether of vintage or modern manufacture, PIO, having a liquid electrolyte, are inherently less stable than dry cap types. I recall @HotBluePlates mentioning that a bunch of expensive modern PIO he bought when starting out turned out to have poor insulation and passed sufficient DC to affect operation.
Yes there are slight differences in parasitic characteristics between different film (and class 1 ceramic) cap materials and construction methods, but for coupling/decoupling filtering applications in audio circuits, the impact of those differences has never been proven to make an audible difference.
For a guitar amp, I'm not aware of any tests that show a measurable difference in the freq response etc from the use of different film or class 1 ceramic cap types.
As with most aspects of our signal chain, Zollner explores the topic https://www.gitec-forum-eng.de/wp-content/uploads/2019/03/poteg-9-2-tone-caps.pdf

Imho one can benefit more from determining the foil side of the caps and thus orientate them right...

I recall checking how my R8 LP was wired and finding that its tone caps were wired on the signal side of the tone pots, ie so even with the tone control adjusted to max resistance, the cap's would be able to pick up any EMI and feed it into the signal path. And to boot, the outer foil was on the signal side, such that even with the tone adjusted to minimum resistance, the outer foil was connected to signal 'hot', rather than signal common.
Its control cavity is unscreened.
As an experiment, I wired one pickup's tone control according to the outer foil rationale, ie with the outer foil connected to signal common, other lead to the tone pot, then the tone pot to the vol control. Both were the modern wiring vol and tone arrangement.
Whether the both tone controls were set to max or min, flipping the PU switch made no difference to the EMI / hum that the guitar picked up.
It was a somewhat rough and ready experiment, and didn't account for the different Burstbucker variant pickups in the guitar. However, I was expecting to hear a difference (how could there not be one?), but whether 'worst case scenario' or 'best practice', the outer foil thing made no difference to a readily apparent criteria.