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Old 19th February 2004, 05:28 AM   #11
SHiFTY is offline SHiFTY  New Zealand
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I'm using 135 kg of transformers
Oh. my. god.

Thats amazing work you have done. Congratulations!
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Old 19th February 2004, 05:47 AM   #12
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Default 833 amp continue

Hi Nick,

you had some questions:

- transformers: allmost all my transformers (power and signal) are made by Heart. Nice stuff. Maybe i'm lucky to live in the Netherlands where there are 3 well respected transformer-"sources" are (Heart, Tribute and AE).

- schemtatic in words: input transformer - 6SN7 - interstage - 300B - interstage - 833 - output transformer. No feedback.

- one of the more difficult things during the building of the amps was sourcing original tube sockets. Some well respected firms made them (RCA, ITT, Johnson) and i managed to get hold of NIB Johnson 124-212's. Most of the 833-sockets are fixed, but the Johnson's can swivel so it was possible to fix the tube socket horizontally but the tube itself vertically. The sockets themselfes are sturdy enough to "hold" the 833.

Now with a picture of the power supply attached. There are 2 umbillical cords from the powersupply to the amp itself:
- one with all the needed filament/bias/B+ for the 6SN7 and 300B;
- one with the 833 needed juice;

Hope this answers your questions ?

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Old 19th February 2004, 06:23 AM   #13
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Default High power on the cheap

For what it's worth i recently heard a cheap chinese Meixing amp where a 300B drives an 805. No idea about circuit details but the sound through a pair of chinese 'red rose' speakers (86db?) was awesome in dynamics, power and soundstage.

If i were to attempt building a similar amp i would probably start by buying a pair of the Meixing monoblocks - any diy effort of similar quality will cost much more than the asking (in China) price.
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Old 19th February 2004, 06:52 AM   #14
cm is offline cm  Singapore
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Any website of the Meixing amp? It will be in Chinese of course but that would not be a problem for me
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Old 19th February 2004, 07:21 AM   #15
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You may try HIFItone. The model i listened to was MC-3008A - the web site pic doesn't do much justice to the looks.
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Old 19th February 2004, 09:24 AM   #16
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Hi Reinout,

Does Heart have a web presence?

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Old 19th February 2004, 09:35 AM   #17
protos is offline protos  Greece
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I was also looking at that model and thinking if the sound quality is up to par.At 900USD it is an absolute steal (Hong Kong) even with shipping it should work out very cheap.
So you say you liked it?Did you compare other amps?
I am seriously thinking of getting one at these prices and of course there are many possibilities of modifications.
But of course there are reservations because it is not a well known brand and I haven't seen any reviews.I wonder if the transformers are good quality as well.
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Old 19th February 2004, 11:24 PM   #18
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I am building a boatanchor amp too.

Will have 5 chokes per channel,
7 mains trans(1.5Kva,200va,80va,50va,10va,200va,160va) per channel
1 output trans per channel.

Just the trans and chokes around 40-50kg maybe more

Will be attempting a stinct in weight lifting if i can carry this much.

Mains trans are cheap to custom wind them. However Opt are hard to be found in my country. They have the core, but do not have the technical skills to do it. Whats your impedance rating of your opt like impedance and current draw? How much where can i ask?

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Old 20th February 2004, 01:01 AM   #19
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Does Heart have a web presence?
Under construction....

But you could visit the other ones by Rik Stoet:



FWIW, when Rik S. started in the early Nineties he had his iron wound in China for his kit amps. No idea if this is still the case though.


P.S. Just spotten this on the second site under "Aanbiedingen" and fell from my chair:

Quad II buizen mono blokken Euro 2.195,00
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Old 20th February 2004, 01:47 AM   #20
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I was also looking at that model and thinking if the sound quality is up to par.At 900USD it is an absolute steal (Hong Kong) even with shipping it should work out very cheap.

From what i remember the price for two monoblocks was around usd1600 from the dealers i visited. You are presumably refering to the Catylink pricing - they seem to be high on everyone's hate-list in the area

I didn't compare to anything - all the dealer had were unknown to me Chinese brands. Don't think i wasn't prejudiced, previous limited experience with Chinese iron was less inspiring. As for the 3008A Meixing, i couldn't detect any bandwidth limiting on the bookshelf-sized rose buds. The mids were obviously coloured, presumably due to the speakers and the peaks had a bit of distortion (volume was set too high) but the huge images and startling dynamics were really impressive. And so were the quiet passages.
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