filter cap question

[Randall]

Guys. I am talking about Power Transformer, not OT. The dimensions of the reissue are different. Mercury is presently the only place that makes one that will actually fit in the reissue chassis. And FWIW, the Mercury OT doesn't really fit the reissue either, it has to be mounted cockeyed, because it is too big to fit the existing space.

[bob p]

I don't understand -- what's wrong with using the Fender PT?

[Chuck H]

I don't understand -- what's wrong with using the Fender PT?

Guys want the MM iron. If you read MM's lit it drives the point home, pretty hard, that their power transformers SOUND better than stock units.

[bob p]

i'm familiar with the marketing and we all know that's BS. i've built several DR and the power transformers' regulation isn't all that different from one supplier to the next. i'm at a loss to understand how the power supplies sound different if they all sag the same amount under load.

[Chuck H]

There use to be a lot more hype and review on their site and elsewhere. Some of it seemed planted. What our commander in chief would call "fake news". But it went on and on. Some reported on how changing to an MM power transformer (not output transformer) really opened up the sound or improved any number of other tonal phrase/aspects. They must have become tired of the constant assault from techs on forums like this one and perhaps even worried that they might be exposed as snake oil salesmen because their site no longer has any user reviews.

I WILL say that of all the OT's available for any number of models Mercury offers the most and more interesting options. They also manage to come out in the top two in any OT shootout (I think there's been a whole two that got any circulation ) So they clearly sound good. But more important is that in those shootouts, there were losers and MM was never one of them. So if you want to KNOW that your OT is snuff you can buy a MM and rest assured. It's a stupid amount of $$$ and most techs, if not most builders, know how to avoid crappy output transformers. Given the choice between a free MM OT or a free Hammond OT I'd take the Hammond. Ok, well, I'd take the MM and sell it, buy a Hammond and go buy a nice dinner for my wife and I with the extra money

[Leo_Gnardo]

There use to be a lot more hype and review on their site and elsewhere. Some of it seemed planted. What our commander in chief would call "fake news".

I'll agree with Chuck, it seems Mercury's "reviews" were written by their own sideshow barkers, ummm I mean sales staff. I never saw such baloney in my life. Well that's not entirely correct either, but about transformers, for sure!

MM's only advantage afaik, is if they are the sole source for some replacement transformer that is completely unavailable. And Heyboer has a good reputation for providing one off builds at reasonable prices when it's called for. I'd use the currently offered DRRI PT and OT without any problem. Funny thing, one customer recently demanded a Deluxe OT from Allen Amps. It's made by Heyboer, costs twice as much as the stock item, but he's paying for it, so there ya go.

[nevetslab]

While I was at BGW Systems in their engineering dept, we sampled and used power transformers from a lot of sources such as Triad, Heyboer, Basler, Schumaker (with their chocplate-coating!), MCI, and later from Pacific Transformer. Randy Nervaka at Pacific used to work at Altec's Ling Transformer division and learned his craft well in the audio transformers. In our Commercial Sound products we had a number of autoformers as well as fully isolated transformers for 25V/70V applications. Triad had made a very decent 15k:15k bridging line input transformer for us after we stopped using Dean Jensen's transforme4rs (cost issues, NOT quality issues of course). Randy then put together some samples for us on the same bridging input xfmr, and they were excellent. Has anyone ever used transformers from Pacific Transformer? Granted they are OEM as so many are. I don't think they ever got into the game with Mercurey and others for replacements to work on the variety of tube amps. They're out in Orange County, CA someplace.

[nevetslab]

Back to Filter capacitors, which is where this thread began.....why is it that just about every vendor of plate supply caps seem to stop at 450VDC in their product line. Only a few sources go to 500V and above. Is it the available insulation materials that are wound between the two plates (in the wound construction) that limits the potential, and not enough sources of thicker insulation is available, or internal assembly methods, or what?

Also, seems like the pickings for axial lead caps is getting mighty thin. Granted, better results are achieved using radial lead designs. In PCB layouts, when I used to make use of axial supply caps, ia also provided solder pads for radial caps when we need to lay them down horizontally. I don't see that being done, or just haven't run across that in current products..apart from being stood up as intended, snap-in or otherwise.

When I was looking thru various cap mfgrs websites last night, I noticed Cornell-Dublier had two of Illinois caps in their lineup. Is Illinois actually produced by CDE?

[Chuck H]

Has anyone ever used transformers from Pacific Transformer?

If by "anyone" you mean any of us, here, I can only speak for myself and say no. If by "anyone" you mean any guitar amp manufacturers, then yes. Trainwreck used Pacific transformers on some units when the NOS Stancor stuff he was using ran short. Pacific even mentions it on their website. Hard to imagine they haven't played that angle harder. Then again, they might be OEM for some bootikee stuff we don't know about.

[Enzo]

why is it that just about every vendor of plate supply caps seem to stop at 450VDC in their product line.

Just my opinion, but I think the higher the voltage, the smaller the market. Darn few things need 500v caps. Tube amplifiers is a teeny teeny part of electronics. We think it matters, but if we all went away tomorrow, CDE and friends wouldn;t miss us. Caps are not so expensive anymore, so look at most big name amps. Instead of a big high voltage cap, we now see a stacked pair of 300-350v caps. Most of our circuits are under 450v by the time we get past the screens anyway.

It isn't a matter of materials or other engineering obstacle, it is just there is no market for them. We are lucky they still give us 450v caps. The main modern use for high voltage caps I can think of is in SMPS. And even there we usually see a pair of 200v caps.

Same with axial parts. Other than us, with our eyelet boards or point to point, who stretches cap leads across a 2 inch space? Other than our itty bitty army of basement builders, even the commercially made tube amps are built on circuit boards, they don't need long wire leads. Even axial lead parts like resistors, these days, the leads take a bend down through the circuit board immediately. No need for long leads.

[Leo_Gnardo]

If by "anyone" you mean any of us, here, I can only speak for myself and say no. If by "anyone" you mean any guitar amp manufacturers, then yes. Trainwreck used Pacific transformers on some units when the NOS Stancor stuff he was using ran short. Pacific even mentions it on their website. Hard to imagine they haven't played that angle harder. Then again, they might be OEM for some bootikee stuff we don't know about.

If I'm not mistook, Pacific supplies Mesa with their iron. Or at least they did years ago. I don't much follow these things. Basler, I used to see them in Peaveys. Now that Peavey means "made in China" I'm sure that game is over. As far as trying to compete with Mercury, I think the executives at any other transformer manufacturer would be ashamed to carry on in the carnival barker / used car salesman mode that Mercury does with the public. Before they claimed to be the greatest thing since sliced cheese, Mercury supplied plenty of power transformers for SWR and I'm sure lots of other amp companies, and I'll bet they did it at competitive prices. Oh the shame...

[bob p]

Hearing that you saw IL caps at CDE surprises me. I've never heard of CDE manufacturing for IL, and CDE has their own inexpensive lines. For that reason hearing that they have IL on their site strikes me as very odd.

Regarding axial caps -- I'll buy them if somebody wants them for an old Fender, but that's about it. I don't like buying Atoms. And the best source for F&T has stupid-expensive shipping charges. If I'm designing something new I'll use Snap-In caps because the selection is better. I either fabricate my own board for them (I've posted photos in other threads) or if I have to retro-fit them into an amp that has axials, then I'll lay them down on their side and run a bus wire to them.

High voltage cap ratings isn't a really big deal since most of the time we're dealing with amps that have cap-input filters in the PSU, which keeps the voltage low during startup. High voltage can become a very big deal if you're designing an amp with a choke-input filter. With those it's common to have a huge overshoot which often requires totem-poling 450V caps so that the turn-on transients don't violate the peak voltage limit. I've had cases where I've had to triple-totem-pole 450V caps with a choke-input filter. In that context the caps start getting expensive. Another method of cap protection is to use a SS device to switch a series resistor in/out of the circuit for soft-start.

[bob p]

Now that the axial parts are being used more for PCB designs than PTP designs, I've noticed that the leads on CC resistors have become a lot shorter. Oh, how I hate that. Now I have to pay attention to lead length when I buy passives. What a PITA. Something else to go wrong when you order if you're not paying attention to every little detail.

As far as trying to compete with Mercury, I think the executives at any other transformer manufacturer would be ashamed to carry on in the carnival barker / used car salesman mode that Mercury does with the public. Before they claimed to be the greatest thing since sliced cheese, Mercury supplied plenty of power transformers for SWR and I'm sure lots of other amp companies, and I'll bet they did it at competitive prices. Oh the shame...

I don't know specific amp companies that are using the carnies' transformers. The only one that comes to mind is Fuchs. The last time I talked to Andy was quite some time ago and he was using Midway Magnetics back then. I've seen a few other booteekie amps that had Midway iron in them. They're pretty easy to spot -- the transformers have the big stickers on them that list the manufacturer and the stock number on them. It's like the iron is shouting to give itself props.

Back in the old days I remember that Midway iron was cheaper than Hammond. That was before they went full-on carnie.

[J M Fahey]

I don't understand why Hammond would tell you they don't have that amp covered.
Everyone in the industry has that amp covered.

Hammond is a big, "serious" Company, making LOTS of things.
They sell their products based on good Engineering and most reasonable price.

Those you call

Everyone in the industry

are actually "Everyone in the Boutique industry", a drop in the ocean (or at least a drop in the bucket) .

WE see them because we are in a niche inside a niche, they donīt evem *exist* in the regular channels.

Does Mouser carry Boutique/Guitar only transformers?
All I can see there are Hammond, and even so many on special order order.

I bet Hammond makes and distributes in Month, say, 20000 transformers or more (of different types) to, say, 100 or 200 Monthly by any of the "specialized geetar" types.

[bob p]

Does Mouser carry Boutique/Guitar only transformers?
All I can see there are Hammond, and even so many on special order order.

I know that Mouser does "carry" the Hammond guitar amp iron. Whether or not they stock them is a different question.

It looks like they do. Here's a parametric search for "guitar output transformer" at mouser:

http://www.mouser.com/Passive-Components/Audio-Transformers-Signal-Transformers/_/N-5gbg?Keyword=guitar+output+transformer&FS=True

http://www.mouser.com/Passive-Compon...former&FS=True

I don't shop at Mouser because they are in Texas, which is very far away from me and transformer freight is expensive. I prefer Digikey and Newark, who are also in the Midwest and offer free shipping. Newark is right in my back yard, so I get next-day delivery on anything they keep in stock.

Newark does stock a lot of the the Hammond specialized guitar amp replacement iron. Back at Christmas time or thereabouts I posted a coupon code to get 20% off of any order at Newark Electronics / Newark.com with free shipping. They carry Hammond iron and they actually keep a lot of it in stock. I purchased 12 different transformers and all but 3 of them shipped next-day from Newark's Chicago warehouse, and the ones that were out of stock were *really* out of stock -- as in out of stock at Hammond. I had to wait 3 weeks for the next production run before they shipped from the Hammond facility on the NY/Canadian border. Everywhere I checked was out of the 2/4/8 and 4/8/16 Bassman OTs.

So even though we are a tiny niche interest group, the big distributors do carry the Hammond lines of guitar amp stuff. Angela and CE-Distribution almost always have all of the Hammond guitar stuff in-stock, and Newark is more reliable about stocking than you might expect.

DIY has become popular here in the USA. IME the bread and butter stuff is easy to find. Sometimes the "smart iron" (like the universal Bassman OT with multiple taps that every tech should keep in stock) sells out quickly. And if you're looking for real oddball iron, like a 6x6L6 OT, that's definitely a special order item. Hammond makes it but none of the big distributors even bother to catalog that one -- I had to request a price quote to order one.