[Sprool (OP)]

One of my interests is tweaking guitar circuits and making stompboxes - analog overdrive pedals, distortion, chorus and fuzz boxes. Here there is a load of mystique about specific resistors and capacitors to capture the true vintage tone. It's common for people to shell out $30 - $40 on a single vintage bumble bee resistor for a Les Paul or an 'orange drop' capacitor for a fuzz circuit. The old and original germanium transistors had a lot of inconsistency in them with current leakage and wobbly bias meaning it was sometimes hard to predict the quality of the distortion. Now silicon transistors are so cheap and accurate they are also a lot more reliable, but the mystique has gone. Some people also rave about certain vintages of op-amp chips for Tubescreamer circuits. I've tried a bunch and can't tell the difference.
Is there any scientific basis for an older non-polar capacitor or a vintage resistor adding some unique quality to the guitar tone?

[graham.d]

Personally, I think it's all b*llocks though there is some truth in the idea that older, valve based power amps sound different. It's nothing mystical though, its just down to trying to match characteristics, which can be done quite well with digital processing. I dabble at guitar playing (just for myself as I'm not very good) and have a Les Paul with a Zoom effects box and Boss Micro-BR digital recorder with a huge host of effects, multitracking, overdubbing, frequency shifting etc etc. It's all quite cheap and remarkably effective. Some of these things are similar to the HiFi stuff in that people with money will spend a fortune on some old guitar and/or amplifier because they can. Whether anyone can really discern that the sound is "better" is doubtful in my opinion. Gibson churn out solid electric guitars by the ton and they are fairly consistent. There can be minor differences in the resonance but I doubt that one's made in the 70's are likely to be magically much better in sound than the production item today. Basically if the construction and the humbuckers have not changed then neither will the sound. 

[SeanB]

If you want germanium transistors i have a few NOS around, most PNP. Noisy little blighters though, I was using them as amplifiers to replace carbon microphones with an electret in an intercom, where the poor performance was an improvement over the original anyway.

As to components making a difference, yes they do, mostly with the differences being in linearity in the signal chain. Old electrolytics do degrade with time, replacing them with modern quality ( not the super expensive hifi grade, just industrial extended temp or aerospace grade) does make a difference. Film units are mostly better, though you will have a hard time now getting polystyrene caps ( the best from a distortion standpoint, but the biggest units with the worst possible assembly, needing heatsinking to keep them from melting when soldering, and needing to be tied to the board with a non crushing tie in vibration environments, along with those thin leads that can break so easily) as noone makes then anymore.

Years ago I got a nice Panasonic 4 channel control centre, and recapped it almost entirely ( only the one little electrolytic was left, even though it was pretty poor, but not in signal path I was interested in using) with some solid tantalums. Power supply now has a 4700uF 63V unit, now it will run for around 5 minutes after power off before it stops passing audio. Original was 220uF and was pretty much open circuit, the ESR being off the scale. Surprisingly not audible as hum. Now used with computer to provide volume control via a knob, and to switch inputs from either TV card or from crappy motherboard audio or the USB audio I installed in the case. Lost the DIN tape connector to put a USB socket in for it.

[syhprum]

A few years back I saw the Bletchly park crowd (Who won the war !) building a copy of an antique computer and for some bizzare reason they were using 60 year old cabon resistors that I remember as being notoriously unstable, I pointed this out but it fell on deaf ears.

[RD]

Ye-olde tube (valve) audio electronics sound different to modern transistor (solid-state) electronics ...

Most audio technicians and scientists theorize that the 'even harmonic distortion' produced by valve tubes sounds more pleasing to the ear than transistors, regardless of style. Many of the musicians who use solid state amplification technology do so for its portability, low cost and high reliability, not its 'tone'. It is the tonal characteristics of valve tubes that have sustained them as the industry standard for guitars and studio microphone pre-amplification.

https://en.wikipedia.org/wiki/Tube_amplifier#Audio_Usage

[Sprool (OP)]

Agree that tube guitar amps sound hugely superior to transistor amps, the circuits are chalk and cheese. I have both a classic marshall valve amp as well as a little peavey vypyr digital modelling amp which is great fun for all the built in effects but the live sound of a hot tube amp is far richer. Digital processor effects are an interesting issue. I have never found a nice sounding digital distortion but for time based effects like reverb and echo digital is far superior flexibility. I think an analog overdrive circuit (4558 op amp) like tubescreamer with diode clipping is a far better sound than you can get from any digital foot effect pedal, I used to have the Boss GT6 unit and overdrive was nasty. Anyway, i remain unconvinced about the presence of vintage resistors and capacitors in a guitar tone circuit.

[graham.d]

The issue with the valve vs transistor amps is probably to do with what happens in overload (close to limiting) rather than what the sound is like when both are in their linear regions. There are lots of loud transients coming out of musical instruments like a guitar and it may well be down to how these are handled by the actual circuits used in each case. It is hard to see how there should be any difference in the sound when operating at low levels, well below any limiting, providing the specifications are the same.

Sprool, as a matter of interest, I find quite a big difference between the effects using Zoom vs Boss. I know they are not intended to be the same but Boss effects seem to be, annoyingly, more treble sounding but have better reverb effects than Zoom. This is just based on my limited experience though.

[Sprool (OP)]

You are right - I agree on Zoom and Boss. The boss multieffects usually have 2 different impedance outputs for headphones, mixer desk or amp. You can switch in a speaker simulator to thicken up the sound, I know if it is set wrong the tone is thin and nasal. Not sure if Zoom have this?
I've never generally liked the Zoom overdrives in particular though, they just sound raspy and synthetic. Still much prefer an analog stompbox sound for overdrive.

[SeanB]

Nice thing about valves is that you can feed in a nominal 0dBV signal, and the overload point is literally 100V plus. It will distort, but hard clipping only occurs at 100Vpp or so.

As to the RECREATED Collosus, they were trying to make it as if it had survived from the war, the only concessions they made were the use of modern power supplies and lead free solder.

[Geezer]

And, as usual, this is all a complete load of boll**ks!

This is all about "how would you like your distortion". AFAIK, the human earbold can only respond to variations in sound pressure. It really doesn't give a #$%^ about how that variation was produced. If you are interested in real Hi-Fi, you should try to reproduce those variations as accurately as possible, even though it might sound like complete %^&*.

If you are going to distort the heck out of it so it "sounds nice", you are not really interested in High-Fidelitee.


(All complaints regarding the post should be sent directly to Sheepy.)

[Sprool (OP)]

Just to clarify, no-one is talking about hi-fidelity accurtate sound reproduction here when you are talking about a loud, overdriven guitar tone.