Converting a Silverface Champ from US to EUR voltage. Transformer question

[mjet]

With SF Champs regularly going for $500+ in Europe, I feel fortunate to have grabbed one in the US for around $220 a year or so ago, although it's sitting in a friend's spare room in Washington DC. I will be there next week and will be shipping it to myself in Europe so the transformer issue has now arisen.

I'd like to be able to play through this without an external transformer so I am looking a replacement export power/mains transformers. I see that Weber sells a few - one with 110v and 230v would do fine - for $40. (There's also one with multiple voltages, but this Champ is staying in Europe.) That beats the pants off of any European options I have for what appears to be the same thing (€ 100 which is $130 now):

http://www.tubeampdoctor.com/product_in ... cts_id=103

If I can swoop in and get one of these for $40 and have my local tech hook it up for me, I'd be a very happy person. I have essentially two questions:

1. Is there something obvious that I'm missing in terms of other parts that need to be replaced?

2. Is there a noticeable difference between the transformers offered by others (for example Mojo), which are a bit pricier?

[zhivago]

I spoke to a few people about this in the past, and they said that the amp needed to be tuned up accordingly...not sure what they meant by that, though...they were a bit cryptic, and almost took my head off when I suggested changing the vintage transformer

for what it's worth, I'd think that yeah, changing the transformer over, should be enough to get the amp working ok...dunno what it'll sound like though.

[Felix]

I don't imagine you would need to change the caps or resistors. I know that there are a few guys in Florida, need to look into it, that offer multi-volt transformers. That is, 110 and a 240v switch installed. There are older Fender tube amps that have this option built in--no mods needed there. I think you'll be okay with a simple transformer change, though the price of $40 seems a lot lower than I've heard quoted.

I think you'll be okay with a multi-tap transformer with no additional mods.
Do you have an amp tech that can help you?

Chris
P.S.Hey Mjet, this is off topic, but how do you like Prague? Are you from there, or did you move there? Just curious.

[mjet]

I spoke to a few people about this in the past, and they said that the amp needed to be tuned up accordingly...not sure what they meant by that, though...they were a bit cryptic, and almost took my head off when I suggested changing the vintage transformer

for what it's worth, I'd think that yeah, changing the transformer over, should be enough to get the amp working ok...dunno what it'll sound like though.

The export transformers are made by some of the same companies which have made export voltage transformers for tons of US-based amp manufacturers, so I'm not worried about a quality difference. It's also a drop-in mod and I'll hold on to the US transformer so putting it back would be possible (and easy). In fact, I'm almost more likely to go this way since I honestly have more faith in a newly-made transformer than a 30-year old one.

I posted this same question over at the FDP (lots of amp techs read the amplifier fora) and I got one further piece of "mod" information:

"...all Champs except the Tweed models run their power tube too hot, so it is best to replace the cathode resistor from 470 Ohms to 820 Ohms or 1k Ohm of 3W or up. Therefore also the bypass cap's voltage rating should be upped to 50V."

This is something I've heard before and I'll follow-through on this to have my local tech (who would probably know this already - he has his own line of amps that he manufacturers and is the best tech in the country) bear it in mind when he's hooking everything up.

The result will in all likelihood be a better amp than the exports which were sent directly to Europe in the 70s.

I don't imagine you would need to change the caps or resistors. I know that there are a few guys in Florida, need to look into it, that offer multi-volt transformers. That is, 110 and a 240v switch installed. There are older Fender tube amps that have this option built in--no mods needed there. I think you'll be okay with a simple transformer change, though the price of $40 seems a lot lower than I've heard quoted.

I think you'll be okay with a multi-tap transformer with no additional mods.
Do you have an amp tech that can help you?

Chris - I'd appreciate it if you could find that info that you mentioned (the Floridians). Yes, I've got an amp tech who I have 110% faith in - I do NOTHING myself when there is current involved.

The transformer for Champs is about the cheapest you can find - go up to 40w+ and you get nearer the $100 range. The $40 one I mentioned is from Ted Weber. If his transformers are anywhere nearly as well-made (and widely-supported) as his speakers, I think I'm safe.

https://taweber.powweb.com/store/magnetic.htm

(The Champ transformers are the first three in the list.)

P.S.Hey Mjet, this is off topic, but how do you like Prague? Are you from there, or did you move there? Just curious.

I'm from the US but moved here 13 years ago. Love it. Can't see myself leaving anytime soon. Feel free to shoot me a PM if you want to hear me blab about it more. 

[Felix]

Hey Mjet!
Yes, I will double check that fact for you.
I'll also be sending you a PM very soon, too.   :)

Check out Marshamps.com -- he is based in south Florida (Weston to be exact). He offers the Heyboer option for $67.50 and I would say that is a good transformer. It's the multi-volt option.

Here is the link:
http://store.marshamps.com/product_info ... cts_id=218

I hope I'm aloud to do that. I'm not entirely sure. But I do  know that if you check them out--good people--you'll get a wide variety range.
110V step by step up to 240V.

[mjet]

You're certainly allowed to link to them - that's one of the many great things about this forum. Thanks for that!

And feel free to PM me about Prague as well.

[JazzBlaster]

if I were you I would save the original equipment as well

[mjet]

Absolutely! I'm a pack rat by nature anyway, but with gear it's a no-brainer.

[Felix]

Hey Mjet -
This is the response I received regarding a transformer change.

"Other than the transformer you will likely need an adapter that changes the American style plug to the European standard of the particular country you will be visiting. They are available in most luggage stores.

The Heyboer Export model has taps for 120, 220, 230 and 240. Inside the amp you only have to change one wire to make a change to the MAINS voltage."

You'll probably have to change the plug, according to my guy, and you will need to change a wire. You may want to double check that though. Moments like this remind me how much I still need to learn about electronics. 

[mjet]

Yeah, I'll have my tech install a Euro grounded plug to the adapter and I'll just roll up the US plug & cable with the US adapter and store it.

I actually pulled the trigger on the Weber transformer - he also sells the Heyboer transformer you mentioned but Weber's "simpler" (just two voltages - US and EUR) seemed a more straight-forward fix than the multi-voltage model. I don't plan on going to Japan anytime soon with my Champ, so I think I'm ok. 

[Felix]

Yeah, I'll have my tech install a Euro grounded plug to the adapter and I'll just roll up the US plug & cable with the US adapter and store it.

I actually pulled the trigger on the Weber transformer - he also sells the Heyboer transformer you mentioned but Weber's "simpler" (just two voltages - US and EUR) seemed a more straight-forward fix than the multi-voltage model. I don't plan on going to Japan anytime soon with my Champ, so I think I'm ok. 

Awesome. 
Glad you got what you need. I'm sure there differences are small or nothing at all. Weber is good stuff.

[mjet]

Yeah, I hope so. The price was great - $48 delivered.

[scottme]

I'm just going through a similar thing now, as I fried the primary winding on my power transformer of my Pignose G40V. Kind of OK, as now I'll have a better transformer with 240V option.

I recommend Weber gear, good product at a reasonable price. Plus the guy who runs the show usually answers your emails.

[mjet]

I've got the Champ and the Weber 240v transformer in Prague now and just need to get it to my amp tech for installation. Weber's service was fantastic - inexpensive, fast shipping etc. It looks like as solid a unit as the original so I anticipate no problems. I'll report it when I get it back.