Hey Robben, where's your Dumble?

[WhopperPlate]

Filter capacitors besides filtering DC are also a pathway two and from ground for your signal. This is why the ESR is important. Furthermore, the dropping resistor combined with the filter capacitors act as a RC filter
CW

This is exactly how it has been explained to me when I have brought it up to those who are more educated than myself. I was waiting for someone to say it better than I could . Cheers

[pompeiisneaks]

My point was more about the implication that 'it's on youtube it must be trash' is a pretty bad generalization and way wrong.

~Phil

That's not at all what i said. Just that having an opinion on YouTube, doesn't make it true.

The definition of implication means 'not something you said but implied' I didn't know 'exactly' what you meant, but the statement:

Wow, he's on YouTube, what he says must be true...

doesn't imply good things, I added the whole other part because that's what I felt you were implying. You maybe weren't... I don't know. Your statement of 'people on YouTube mocking others isn't a good way to do things' seems contradicted by you mocking someone on YouTube that's pretty damn smart. That's all.

I too am not trying to start a debate, just personally have watched a LOT of his YouTube videos and like his point of view, and mostly trust him to know what he's talking about as a career professional Electrical Engineer. So I'm probably being a bit overly defensive. I also am a YouTube creator and know that a LOT of them are clickbait garbage with no idea what they're talking about and still imply they do, but not all are. E.G. I don't disagree with some factual basis to your overgeneralization of YouTube, but I don't automatically categorize all YouTubers just because they're on YouTube in that category.

I may be misunderstanding this, but it seems to me that you're getting defensive about anyone questioning your opinion (with no basis other than 'if you hear it you'll know') must be believed and accepted as fact or else...

I am perfectly happy if you feel this is true, and you can continue building amps in whatever way suits you. I, on the other hand, have a more scientific approach to everything, and although I 'trust' my ears I still live by that maxim 'trust but verify' as well.

At any rate, I'll stop the thread derail.

~Phil

[Richard1001]

My point was more about the implication that 'it's on youtube it must be trash' is a pretty bad generalization and way wrong.

~Phil

That's not at all what i said. Just that having an opinion on YouTube, doesn't make it true.

The definition of implication means 'not something you said but implied' I didn't know 'exactly' what you meant, but the statement:

Wow, he's on YouTube, what he says must be true...

doesn't imply good things, I added the whole other part because that's what I felt you were implying. You maybe weren't... I don't know. Your statement of 'people on YouTube mocking others isn't a good way to do things' seems contradicted by you mocking someone on YouTube that's pretty damn smart. That's all.

I too am not trying to start a debate, just personally have watched a LOT of his YouTube videos and like his point of view, and mostly trust him to know what he's talking about as a career professional Electrical Engineer. So I'm probably being a bit overly defensive. I also am a YouTube creator and know that a LOT of them are clickbait garbage with no idea what they're talking about and still imply they do, but not all are. E.G. I don't disagree with some factual basis to your overgeneralization of YouTube, but I don't automatically categorize all YouTubers just because they're on YouTube in that category.

I may be misunderstanding this, but it seems to me that you're getting defensive about anyone questioning your opinion (with no basis other than 'if you hear it you'll know') must be believed and accepted as fact or else...

I am perfectly happy if you feel this is true, and you can continue building amps in whatever way suits you. I, on the other hand, have a more scientific approach to everything, and although I 'trust' my ears I still live by that maxim 'trust but verify' as well.

At any rate, I'll stop the thread derail.

~Phil

Thank you for explaining to me what i meant, implied, and how i feel about things. I often don't know myself and it is refreshing to have someone else than my girlfriend helping me understand myself.

[dorrisant]

Um... Total derail. Can we get back to our regularly scheduled event?

[talbany]

Um... Total derail. Can we get back to our regularly scheduled event?

I don't know? I was rather enjoying the discussion on filter caps

Tony

[dorrisant]

Um... Total derail. Can we get back to our regularly scheduled event?

I don't know? I was rather enjoying the discussion on filter caps

Tony

Agreed. I think it is a derail to argue "Wow, he's on YouTube, what he says must be true... " Maybe he doesn't realize how much Phil contributes on YouTube, or here for that matter.

Also, "Thank you for explaining to me what i meant, implied, and how i feel about things. I often don't know myself and it is refreshing to have someone else than my girlfriend helping me understand myself." That parts seems a bit too aggressive.

I just think "agree to disagree" should be invoked so we can get back to the filter cap discussion. No offense to you, Tony.

[dorrisant]

Has anyone documented the ESR of the Sprague caps? I'd like to measure my favorites and compare. I have a diy ESR meter but the scale is not true to any real measurements. It is a 50 uA meter that shows 50 uA as zero ESR and the highest ESR would be 0 uA. Great for repairing and comparison but not definitive.

[ijedouglas]

Has anyone documented the ESR of the Sprague caps? I'd like to measure my favorites and compare. I have a diy ESR meter but the scale is not true to any real measurements. It is a 50 uA meter that shows 50 uA as zero ESR and the highest ESR would be 0 uA. Great for repairing and comparison but not definitive.

Hey Tony,

I did a bunch of tests with an ESR meter to try and find a correlation between ESR and what I was hearing. This was a crappy Atlas ESR70 so no super scientific experiment. I was unable to find a correlation between ESR and tonal properties. In discussions with others, the consensus was that the higher the ESR, the duller the cap. This didn't hold true. Some of the caps I tested (NOS Sprague TVAs) has an ESR of 3.5R but they sounded bright and clear. I also tested Elnas that had a low ESR but they had a duller top-end. I tested a bunch of others and really couldn't find a pattern. BTW, all of these tests were on cathode bypass caps.

[WhopperPlate]

what year was 102 powersupply Serviced? was it just the filter caps that were replaced ?

I wonder how Robben personally feels about the current sound . I know I have read and heard others mention that he’s been talking a lot recently about how 102 doesn’t fit in the musical situations he’s found himself. Maybe there’s more to the story

[Synchu]

As I implied (seems that's the trend of the day) from some interviews and YouTube videos, he seemed a tad bored with the 102 and hence might be just looking for some variety ...

Niki

[talbany]

Um... Total derail. Can we get back to our regularly scheduled event?

I don't know? I was rather enjoying the discussion on filter caps

Tony

Agreed. I think it is a derail to argue "Wow, he's on YouTube, what he says must be true... " Maybe he doesn't realize how much Phil contributes on YouTube, or here for that matter.

Also, "Thank you for explaining to me what i meant, implied, and how i feel about things. I often don't know myself and it is refreshing to have someone else than my girlfriend helping me understand myself." That parts seems a bit too aggressive.

I just think "agree to disagree" should be invoked so we can get back to the filter cap discussion. No offense to you, Tony.

I thought you were referring to the O P Robben's Dumble derail. Back to caps
no offence taken.

Btw F&T was sold in May 2018 to Mersen
https://www.mersen.com/news/mersen-purc ... tion-ftcap

Tony

[martin manning]

We're a long way from Robben Ford playing this or that amp, though ;^)

On ESR (or the equivalent tan d, or D factor) of power supply filters, that's pretty much all you have as a figure of merit, other than the capacitance itself, and both of these will have some production variation. It's known that power supply ripple voltage interacts with the note frequencies, and can make an audible difference. Increasing ESR has a small effect on the ripple voltage, so you might think it would be noticeable. I found an increase of 280mV out of 8.7V ripple (+3%) in a simulation where I added 1 ohm in series with very low ESR (120 mΩ) 220u caps in a stacked reservoir. That doesn't sound significant to me considering its a 9x increase, but it would be easy to do a test in hardware by adding some 1Ω resistors. The same thing would happen if the total capacitance were 3% lower. In general I don't think typical variation in ESR is going to be significant at audio frequencies unless it gets so high that the ability of the filters to decouple gain stages is compromised, as in failing filter caps. It is very important in applications like SMPS, where both high frequency and high ripple currents are present.

[FUCHSAUDIO]

Yeah I was going to mention that also. Robben sounded really great playing that Fender guitar. Now having said that, I understand why Andy probably doesn't care much for Paul Reed Smith, and from what I heard, I wouldn't either. I will not say anymore than that.
CW

I'm just not understanding Robben's current gear choices. I know he (and maybe also Carlton) sold (some of) their Dumble's to fund divorces. Man, I get that now totally, being divorced myself. As far as current tones and gear choices, I'm not getting it with Robben. Larry is moving a signature guitar now, so hey, it's a nice revenue stream for him.

Dude, someday I may just write a book about some of my encounters in this industry. I've spoken with too many people who just had the most amazing horror stories. Me and Matt Garcia spent an afternoon on the phone sharing stories about our encounters with the guy from Maryland. This amp look familiar ? Matt and I both did the dance with him...enough said.

https://www.vintageguitar.com/3512/garc ... att-combo/

[WhopperPlate]

he seemed a tad bored with the 102

I usually only get bored with amps that don’t do what I want.

Whatever the known and unknown parameters that may effect a capacitors tonal effects within an amplifier, I would bet money if those caps in 102 were changed to even just sprague he wouldn’t be searching so hard.

Who knows Robben ? Who can pass along the memo? lol All I know I can say is once I started swapping caps in my own builds it was what made the difference I needed. If he isn’t happy it
Would be cool to make him happy . I am sure though everyone is afraid to touch a wire in “Alexander”

[Synchu]

he seemed a tad bored with the 102

I usually only get bored with amps that don’t do what I want.
.....

My reading is that you need more amps

Niki