Page 2 of 2

Re: Capacitors in Mesa Boogie Dual Rectifier

Posted: 23 Jul 2019, 23:48
by Optical
You were presented with very clear evidence, not anecdotes - Did you read the link with the well presented data? Why is that data not good enough? Do you see errors in the way the tests were conducted?
That cap thread is mostly talking about low signal voltages and mostly not talking about low class ceramics or very large signal voltage swings. Your data seems to be low level too and gets a result i would expect and agree with, but that's not what we're talking about here, right?

By gritty texture, what was intended to mean was the harmonics created, because of the aforementioned nonlinearities. I'm open to suggestions on how you would better describe the sound that a cap changing value dependent on frequency and signal level makes... Apologies for using laymans terms.

I'm all for debunking cork sniffers with their capacitor choices, i cant hear any difference between a wima, sozo, mustard, panasonic etc film cap.
But a low class ceramics in certain positions vs film is quite different. The original question was why did Mesa use low class ceramic caps in that position, and the reason is because in that position they have a different sound to the poly film caps they use elsewhere. You haven't been able to provide any evidence to the contrary so just be happy with whatever you want to believe is as i dont know why i'm bothering to reply at this point :)

Re: Capacitors in Mesa Boogie Dual Rectifier

Posted: 24 Jul 2019, 00:06
by FiveseveN
Tell you what: I'm gonna get a Recto from our studio, put that cap on a switch with whatever film alternative you deem satisfactory and run a proper test. Only thing is I can't promise I'll have time for that before the end of August.

Re: Capacitors in Mesa Boogie Dual Rectifier

Posted: 24 Jul 2019, 08:38
by bmxguitarsbmx
ESR is going to be the dominator in the cathode bypass cap position. Though, tantalum may be the least linear cap type.

I don't have any 1uF Vishay 173D, but here are some 1uF caps I have on hand:
ESR for the Nemco tantalum is 24 Ohms @ 120Hz.
ESR for Electrolytic is 60.62 Ohms @ 120Hz
ESR for Grey 100V box cap is 5.90 Ohms @120Hz
ESR for Red 105J100V is 4.17 Ohms @120Hz

Measured with EXTECH 380193

I did actually presort these caps to be within 5% of each other in capacitance value.

Re: Capacitors in Mesa Boogie Dual Rectifier

Posted: 24 Jul 2019, 12:18
by phatt
In the end you are still faced with *The Law Of Diminishing Returns* :wink:
It's how much difference is actually heard. [smilie=a_whyme.gif]
I'm not disputing the science, just the amount of effort for return as a lot of tweaks actually don't cause the night and day difference often claimed.
I have no doubt some tricks work well but a lot is hype, Like 600V tone caps in guitars, Good caps but not needed in that situation.

Often a qualified statement is taken out of context and suddenly orange caps are better than brown. :slap:

Much like oxygen free copper wire delivers a better sonic result,, while in truth it's real benefit is purely a mechanical one, apparently it reduces cracking around solder joints. Great for Aerospace gear where vibrations are extreme but does sweet bugga all for improving audio transfer.

Hey *FiveseveN* I'd be interested in the results,, keep us posted. :thumbsup

Re: Capacitors in Mesa Boogie Dual Rectifier

Posted: 27 Jul 2019, 19:11
by bmxguitarsbmx
If you want to put in the least effort, replace the part with the same part. Vishay 173D. I would verify the voltage rating.

If you want to drastically change the tone, change the value of the part. I think everyone can agree on this.

Re: Capacitors in Mesa Boogie Dual Rectifier

Posted: 06 Aug 2019, 23:33
by Optical
Here's something we can all argue on the internet about

3 caps swapped in a jcm800, these would be two treble peakers and the treble cap