Noob Power transformer for Tubelab SimpleSE

[dubdub]

Hi

I am considering getting the tubelab SimpleSE PC board but can anyone recommend a power transformer I could use with the board suitable for UK voltage. This might be a dumb qestion but thanks for your help!

Al

[cbutterworth]

Al,

Hammond do a 300 series trafo with 375-0-375 on the secondaries as well as 6.3 and 5V. It is rated for 175mA and has universal primaries (i.e. can be wired for 240V).

Take a look on their website (www.hammondmfg.com) for the correct model number.

This is the one that I plan on using for my SimpleSE, although the entire build will take a few months as I have to save each month to buy components - the result of having recently paid for expensive dog surgery!

Charlie

[dubdub]

Hi Charlie

Thanks for your reply, since the board was made in the USA I wasnt too sure if there was anything I should take into consideration regarding mains voltage differences (I didnt want to use the wrong part!). That Hammond Universal should do the trick

May I ask how you are finding things with the board? Have you built tube amps before?

Kind Thanks

Al

[cbutterworth]

Al,

I have yet to stuff and solder the board. Once the transformer has done it's work and converted mains AC to 750VAC (375-0-375), I guess that there is absolutely no difference between the SimpleSE here in the US or in the UK. Although check the Region Code on any DVDs you'll be running through the SimpleSE ! SORRY only kidding.

The SimpleSE will be my first tube amp. I have built a SS power amp from a kit, and have built an Aikido tubed preamp using Broskie's board. The SimpleSE will be run with CD / iPod input straight into speakers. I couldn't source the 80uF ASC motor-run cap, but have a couple of 45uF GE motor-runs, which I'll parallel.

My advise is to work on the SimpleSE in as methodical a manner as possible and don't try to rush it. Also, if mounting components of different sides of the board, be sure to check polarity where it is important like caps and the solid-sate components.

So how is the weather other there in Blighty? My folks live in Rochdale (nr Manchester) and have been complaining bitterly about the inclement weather of the recent weeks. I assume that you have survived the flooding.

Charlie

[tubelab.com]

Thanks for your reply, since the board was made in the USA I wasnt too sure if there was anything I should take into consideration regarding mains voltage differences (I didnt want to use the wrong part!). That Hammond Universal should do the trick

The Hammond part number that you are looking for is 374BX. There may be transformers available in the UK with similar specs that are cheaper that importing a Hammond from the US or Canada.

The power transformer is the only thing that must match the mains voltage available in your area. Everything else is the same all over the world. The "universal" Hammond (or others) can be used most anywhere in the world, although the primary wiring must be changed when moving to a different mains voltage. SimpleSE boards are happily playing in the UK, Australia, Greece, and Thailand.

I couldn't source the 80uF ASC motor-run cap, but have a couple of 45uF GE motor-runs, which I'll parallel.

The paralleled 45uF caps would be fine, and if a decent quality electrolytic is used in the PC board one 45uF cap would probably be fine. The same seller that was offering the 80 uF ASC caps now has 100 uF motor run caps from another vendor. Builders report good results with these but I haven't tried them yet.

Although check the Region Code on any DVDs you'll be running through the SimpleSE ! SORRY only kidding.

I have a German Apocalyptica concert DVD (3 cello players and a drummer covering Metallica tunes) that my DVD player spits out. Windows Media Player seems to digest it just fine, and with a 24 bit 192 KHz external sound box, it sounds real good through a SimpleSE.

[cbutterworth]

George,

Your PCB arrived fine, Thank-you. I may get to stuff it and solder the small parts this weekend. The rest will have to wait a while. I need to stick with the family budget of $50 per month for personal projects, which means a couple of months to finish buying parts. I'll build a wooden sided chassis as pine or poplar is cheap and use a piece of aluminum for the top plate. I expect that All will have his finished by that time.

My only problem is that summer will be in full force when I am likely doing the final assembly and my workbench is outdoors (albeit under shade). The 110F or higher AZ temps mean that I only get a couple of hours for working on projects. If all goes well, I may get the SimpleSE finished in time for summer rather than during it!

Charlie

[dubdub]

Originally posted by cbutterworth
Al,

So how is the weather other there in Blighty? My folks live in Rochdale (nr Manchester) and have been complaining bitterly about the inclement weather of the recent weeks. I assume that you have survived the flooding.

Charlie

Dont get me started on England's weather I could bore you all day! Nah, for the past couple of years or floods have hit pretty hard, we're luck because we live in Birmingham which is in the midlands and not close to rivers or flood planes- other than that the weather is the same as usual- schizophrenic!

Thank you guys for the advice about the power transformer, I shall certainly be mindful of playing my region 2 DVDs through it though!

Thanks agin !

Al

[tubelab.com]

My only problem is that summer will be in full force when I am likely doing the final assembly and my workbench is outdoors (albeit under shade). The 110F or higher AZ temps mean that I only get a couple of hours for working on projects. If all goes well, I may get the SimpleSE finished in time for summer rather than during it!

Pretty much the same in south Florida. Temp in summer is 95 to 100F with 80 to 100% humidity. All of my wood and metal work must be done outdoors also. Everything is covered in sweat within 30 minutes. This winter has been unusual, only 3 days since November under 75 degrees. This weekend I will replace my 15 year old AC unit, maybe then I can do better than 80F inside the house. Playing with electricity is not fun or safe when you are all sweaty.

I have tried to get caught up on some projects during the cooler months, but too many unfortunate events have derailed those efforts this year. I got one PC board operational, and built no new amps this year. I did 3 last year.

[nhuwar]

You want to talk about nasty winter weather I live in New England. Guess it could be worse I could be in Siberia.

[cbutterworth]

My first exposure to the US was grad school in Iowa. I loved the winters, although good downhill skiing could have been closer!

At -20, you can pile on the clothes and take the dog for a brisk walk. At 115, if you remove all your clothes, you get sunburned, the cops arrest you, and the dog watches from the air-conditioned house

Charlie