Does an D-Stile Amp need time to burn in?

[Structo]

Oh and by the way, not sure if a light bulb current limiter forms caps but I too always start a new build with one.

I hate the smell of burning transformers and other expensive components.

[Zippy]

After 30 years or so drawn copper has relaxed back into it natural orientation, that's why silver face and now 1980's amps are starting to sound better.

Residual stresses may be relieved but grains will not reorient themselves.

If a silverface is starting to sound better, it's more likely due to aging ears. I don't know that I'll live long enough for a Peavey to sound good.

[Luthierwnc]

Tony, my comment was basically that it has to have some things going for it early on -- or improve quickly with some alterations. If the amp is clearly not a good prospect after you have given it an opportunity to shine, they probably won't get better by themselves.

My disadvantage is that I don't make enough of one kind of amp to: a) know exactly what I'm looking for or b) compare them to one another. Once I have what I like (and that might take a while), I'll get some new wild hair and try that -- probably with an amp that didn't make it as something else. sh

[talbany]

Tony, my comment was basically that it has to have some things going for it early on -- or improve quickly with some alterations. If the amp is clearly not a good prospect after you have given it an opportunity to shine, they probably won't get better by themselves.

My disadvantage is that I don't make enough of one kind of amp to: a) know exactly what I'm looking for or b) compare them to one another. Once I have what I like (and that might take a while), I'll get some new wild hair and try that -- probably with an amp that didn't make it as something else. sh

Thanks for clarifying.. Yeah sure an amp that comes off the smoke test that needs tweaking or isn't operating properly (we've all had those)..
Time won't cure an in-properly set up or flat lifeless sounding amp..
Tony

[BobW]

Hi,
I'm surprised that noone has mentioned forming filter caps. I've been told that it takes some time to fully form the electrolytic in the filter caps and this has a pretty big effect on tone. I have seen amps that sounded like a** at first that got much better after a couple days of burning-in. I've got a new D-Type build now that's a bit harsh. I'm hoping it'll mellow after a burn-in and the E-caps get good and formed.

IC had a really good PDF on the subject.. (Cant' find it) It basically said Forming filter caps was primarily maintance/safety practice used back in the day when the shelf life of caps was much shorter than modern caps/ materials used today or like Tom says if the amp has been sitting long periods of time( although this was called reform).. Many techs adopted the technique thinking it helped prolong the caps life (although this was never actually proven) at the voltages we run..nor has it been proven to enhance or change the sonic character of the amp.. At least not that we can hear..It's one of those things that won't hurt to do just don't expect your amp to sound or perform better..

Lucky me I just scored forty year old Fender twin transformers for my #124 build.

Steve congrats on the find..
Tony :

Is this it?

https://tubeamparchive.com/viewtopic.ph ... t=nichicon

[Structo]

I know that Larry is a big proponent of reforming old caps.
He has stated that he has NOS electrolytic caps of the type that were used in Marshall amps (Hunts? LCR?)
Anyway, these are the radial can caps and he said he puts them in hot water to a level just below the top and heats the paste this way then takes them out, dries them off and applies voltage through a 100K resistor or variac.

He said the heat helps decrystalize the paste and helps the reforming process.

[talbany]

Is this it?

That's a post from a while back right before I began researching the subject..( Bob if your referring to it as the PDF then no)..This was a document published on the web by I am most certain Illinois caps ...After the post I did research the subject formed caps on several amps off the line called several in the know and still have yet to see any real evidence that supports cap forming (New unused caps) effects tone..I dropped it pretty quickly..

If anyone has conclusive sonic evidence or even a strong opinion on the subject please post it..Love to read!!Thanks..
Tony

[talbany]

Found it.. It was actually Sprague that put it out not IC..

Here is a quote from appendix C of the 1990 Sprague electrolytic capacitor
catalog. Published
³When aluminum electrolytic capacitors were first developed,
deterioration ³on-the-shelf² was a major problem and frequent
replacement of stock parts was necessary. Additionally, use of capacitors
for extended periods at small percentages of rated voltage permitted the
dielectric oxide film to ³deform², just as it would ³on-the-shelf². Both
problems were solved in the early 1950¹s with the introduction of
high-purity aluminum foil. Oxide film stability was greatly enhanced and
today aluminum electrolytics can be used after storage, and at any
percentage of rated voltage, without loss of capacitor quality².

Is this advertising BS.. Could be!!..No real evidence to suggest otherwise.(That I could find)

One last point. Sprague publishes application note number 3499.1 titled
³Reconditioning Procedures for Sprague Aluminum Electrolytic Capacitors².
Therefore, they are admitting that, under certain circumstances,
reconditioning is beneficial.

Forming insures the electrolyte is not dried up and that the oxide coating is even.When a cap sits for a long time with no voltage/current applied the electrolyte begins to dry,and the oxide coating begins to get "spotty".How long is too long?I dont know
I would tend to believe the ESR (Like Bob points out) value would have more to do with tone than cap forming(Changing the R in RC).. Talking to myself!!


( ESR varies with frequency for a given capacitor, and is "equivalent" because its source is from the characteristics of the conducting electrode structures and in the insulating dielectric structure)

How did I get this far gone!!



Tony

[Structo]

Sorry to bring this up but just read Tony's post and had me thinking again.

Ok, we can all agree that an aluminum electrolytic capacitor has a wet electrolyte paste in it, right?

So if a cap sits on a shelf for 5 years or however long of a time period and this paste dries, maybe not completely but lets say it has lost half of it's moisture.

I don't think any amount if reforming is going to replenish that fluid that is gone.
Anybody know what the liquid is that makes up the paste?

I know some guys at another vintage amp forum were touting that they had NOS E caps that they had reformed and used.

I guess what I am asking is, why would you do that?

I can see doing it to caps that are in an amp that hasn't been played for quite a while, but once those caps have dried, I don't think there is anything you can do is there?

If they have improved capacitors over the years, which I can only assume they have, then aren't they better than ever right now?
Why would an old one be better?

Why would any old cap be better than current production?

[mojotom]

Just my 2 cents about transformers.

I own some great vintage amps including a 66 Superreverb and a 66 JTM45 and I got the opportunity to make some tests and AB and empirically speaking I think a 40 years old output transformer is a big part of the awesome smooth sound I got from both. I eventually removed them and try them in new amps and found that effect too. Still components do play a role too for sure but that one seems important.

Funny enough I do think old pickups got something too because the pickups of my old (66) Jazzbass make any jb sounds great.

Ok I might be a 66 kind of guy but a player amp or guitar is played because it sounds great and the more they have been used the more they sound good in a way.

I've learn some things from Alexander and the old output transformer was one of the first thing I was told.

[talbany]

Just my 2 cents about transformers.

I own some great vintage amps including a 66 Superreverb and a 66 JTM45 and I got the opportunity to make some tests and AB and empirically speaking I think a 40 years old output transformer is a big part of the awesome smooth sound I got from both. I eventually removed them and try them in new amps and found that effect too. Still components do play a role too for sure but that one seems important.

Funny enough I do think old pickups got something too because the pickups of my old (66) Jazzbass make any jb sounds great.

Ok I might be a 66 kind of guy but a player amp or guitar is played because it sounds great and the more they have been used the more they sound good in a way.

I've learn some things from Alexander and the old output transformer was one of the first thing I was told.

Mojo
Several years back Lou Toomey from B&D sent me a Power and OPT off a 66 Plexi he had laying around.. I used them to build him a Twreck style amp in a small type head.. Coupled with a pair of NOS Amphrex 34's and 12ax's the amp really was quite spectacular..With a good sounding Paul was like boing!!.. He actually used the amp on several shows but had to pull it as it was simply put this thing is too F&$kin loud.. Pretty funny.. This was the first one that made me begin to believe there was something more to used iron than led to believe..Doubed Shipwreck

[llemtt]

66 Superreverb and a 66 JTM45... awesome smooth sound I got from both

do you have at least a bare idea of how those amps sounded back in 66?

something tells me they were awesome smooth since their first day

cheers
teo

[Zippy]

66 Superreverb and a 66 JTM45... awesome smooth sound I got from both

do you have at least a bare idea of how those amps sounded back in 66?

something tells me they were awesome smooth since their first day

cheers
teo

+1

This brings out the issue of winding configuration vs aging of components.

[mojotom]

Well, those two amps are definetely not any Super reverb and JTM45 but the best two I have found and to me these were awesome sounding when they were first fire up but I do think aging help a lot and when I put the OT in other more modern amps they do have a smooth effect for sure.

I build my first Dumble a couple of month ago with an aged twin OT, will try Mercury along the year and will report back.

I've try to understand what make these amps so nice and I think the aged OT is the main answer, I've tried several speakers with them and they do affect the sound but not to that extend.

[Luthierwnc]

Going back some time now, I was one of the guys who was pretty happy with the mono/stereo trannies in the flea-market projects. It might have been my tin ear but one of the best amps I ever made was a Spitfire clone out of an Eico something-or-other with a pair of 6BQ5s. Course, sometimes they got the frequencies all wrong -- but there were moments.

Devices of the time were serviced, not replaced. Labor and material costs allowed room to overbuild since it cost so much more to do (or subcontract) warrantee work. Plus, the manufacturers themselves were responsible for the supply chain and PR. The pro builders on this forum service the high-end of the market personally but the middle and low end of the gear market can't do field repairs. If it is covered, the dealer will give you another one, ship the original to a quasi-production facility who resells it as a second. If something fries, it won't be a trannie so why spend any more than you have to?

I can't speak to whether time and heat mature a transformer. It works with wood. sh