help choosing capacitors: mallory 150 vs juniper vintage tone vs orange drop ..

[SoulFetish]

Oh, and I see your point, Juan. But I've seen so many high end mass produced electronics fail miserably from component failure.
But while I don't believe for a second that large scale manufacturing is incapable of high quality standards, at the same time I don't believe that it guarantees it either.

[soundmasterg]

Not all orange drops are film and foil construction. Type 725M is metalized polypropylene, and type 425M is metalized polyester.

Sorry, I should have been more clear what I meant. I was mainly talking about the common ones used in guitar amps or available at the usual suppliers...the 715P, 716P, 4PS, etc. Most people don't search out the other types.

Greg

[mikepukmel]

Thanks to everyone, what a great discussion.

[nosaj]

Juan, the only thing I want to know is: How were you able to embed such big pictures??!
I've been trying to do that forever. Is it because they have an http address, and are not an attachment?

(sorry for going off topic)

He has Mojo and doesn't even know it.


nosaj

[J M Fahey]

Oh, usually avoid attaching images (specially schematics) because this Forum Server now and then crashes in mysterious ways and only serves a 1 pixel .gif instead of what it´s asked for.
So I usually click the Image icon on top, paste the http link but do NOT select the "upload and attach" checkbox , just let Forum grab it from wherever it is on the Net.

Mind you, sometimes they also disappear but in general it´s the lesser of two evils.

As of modern parts reliability: yes, of course, a few fail, and we get to see *those*, precisely because we are Service guys ... that said if same products were built with old NOS parts they would fail even more
WAY more.

[mikepukmel]

Well, for better or worse (hoping for better tonewise), I put Mallory 150's for signal caps in my cart at Hoffman Amps. I used ceramics in a few places only because the 'vintage' layout for the AB763 doesn't leave much room in these spots, and ceramics are cheap. The electrolytics are a pain.

A few of you gurus mentioned this, but Im seeing it now: The farther the value is from the "vintage amp" values, the cheaper the component gets. The exception is 22uf/25v or 22uf/50v nichicon's that are 81 cents! (cents!!!) compared to 3.00 and up for 25uf/25v or 25uf/50v. Will see what kind of tone I get out of this thing.

Thanks for all the help and cool discussion.

[Leo_Gnardo]

The farther the value is from the "vintage amp" values, the cheaper the component gets. The exception is 22uf/25v or 22uf/50v nichicon's that are 81 cents! (cents!!!) compared to 3.00 and up for 25uf/25v or 25uf/50v. Will see what kind of tone I get out of this thing.

You could use anywhere from 10 to 10,000 uF caps as preamp channel bypass and not notice any difference in tone. I found a knock-down sale on 20 uF 25V a couple years ago, pennies each by the hundred, that's what I used until they ran out. I'm sure not even the best "golden ears" could tell the difference between those and 22 or 25 uF parts.

[g1]

If you are willing & able to use radial instead of axial leads, you will see even further cost savings.

[nsubulysses]

You could use anywhere from 10 to 10,000 uF caps as preamp channel bypass and not notice any difference in tone. I found a knock-down sale on 20 uF 25V a couple years ago, pennies each by the hundred, that's what I used until they ran out. I'm sure not even the best "golden ears" could tell the difference between those and 22 or 25 uF parts.

I don't claim to have golden ears but I feel like saying, just for the sake of mikepukmel who seems to be learning a lot about this kind of stuff right now, that although 22uF to 25uF would never be notieceable, 10uF to 25uF is a pretty noticeable differnce IMO. Especially in a high gain amp or even a clean amp that gets pushed to overdrive. Bigger cathode bypass caps boost so much bass you lose a lot of note articulation on pick attack and also the overdrive tone will tend to be flabby and flubby from too much bass. Less bass makes the tone less likely to "fart out" in some sort of nasty overdrive way, as they say.

Look at this chart for cathode bypass cap frequency response (mikepukmel) to see what I mean. When you get up to abuot 25uF the whole audible frequency range is bypassed (boosted). You can choose a lesser value cathode bypass cap to limit how low the low frequency response boost reaches.

[Enzo]

Yes, but look at the frequencies at 10uf. A guitar goes down to about 80Hz, right? At 80Hz, the 10uf show way less than one decibel drop.

[nsubulysses]

Yes but almost no one plays in standard tuning anymore. Even black sabbath and Jimi Hendrix didn't play in E standard way back when, and that was almost 50 years ago.

I play in A standard and switching from 2.2uF, 4.7uF, 10uF, 22uF...............all sound noticeably different. I could be wrong but I think with A standard being almost a whole step down that might almost reach bass low E range, 40Hz or so. right?

Maybe my ears are more golden than I think

also 80 Hz for guitar E string, but what about artificial bass that is created by harmonic distortion which is below 80Hz??

[Leo_Gnardo]

Maybe my ears are more golden than I think

Maybe so, and if that's the case good for you!

As Enzo says, the difference at the low E fundamental is less than 1dB. To my ears, the low end doesn't begin to dry up until I install a bypass cap (on a typical 1K5 cathode resistor) 4.7 uF or less. 3.3 uF is plenty for just about anything, but that's my opinion and I'm sure anyone can and will kick it in the pants. In some cases there's a clear advantage to limiting low frequency response this way, especially when stages are to be cascaded for overdrive.

I must be working for those almost nobodies. A heckuva lot of my crustomers don't down tune, many of them are playing jazz and traditional rock.

[Dave H]

Yes but almost no one plays in standard tuning anymore. Even black sabbath and Jimi Hendrix didn't play in E standard way back when, and that was almost 50 years ago.

I play in A standard

It's good to know I'm almost no one Hendrix dropped to Eb (78Hz) didn't he? Surely you're not dropping down to A (55Hz)? I'm out of touch.

[nsubulysses]

yes sorry to make a big assumption. Come to think of it I can only recall having 1 jazz musician customer ever. whoops I apologize

I'm not sure but I guess A would be 55Hz? When I say A standard I guess it is basically the equivalent of the 7th string to a 7-string guitar which is A, but instead it is a 6 string guitar. So heavy (.070 gauge) top string tuned to A and high A (I use .014) for the bottom string.

Lots of metal bands of the 80s and 90s tuned to E flat, D, C#, etc. If they used dropped D style tuning and tune down as well some of them were even lower. Carcass tuned to B standard and their first album was in 1988.

Hendrix did a half step down. Please correct me if I'm wrong because I'm not a great black sabbath fan but didn't they tune to D standard or C# standard or something?

A local band that is pretty well known and tours out of the country regularly tunes to ............F#

Anway, I guess that is a bit extreme, and particular to extreme genres. Like, when is the last you heard "jazz musician" and "Carcass" within a few paragraphs of each other.

[SoulFetish]

What determines the -3db low frequency cutoff is the the combination of value of the cathoder resistor, in parallel wirh the tubes internal resistance when looking into the cathode, As well as the value of the capacitor. Not just the cap value.