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Amp Building for a novice

andy831

andy831

pfm Member
My new loudspeakers have arrived and it seems very likely that I am going to need a much more powerful Valve amp than I presently use.

I am not "gifted" practically, in fact I am a complete novice when it comes to the soldering iron. I can however read plans and therefore assume I could read a circuit diagram.

Having looked inside several point to point wired set amps with no circuit boards, the internal Architecture does seem very simple, or am I over simplifying what i think I can see???

I am therefore considering maybe building an 845 Architecture Set amp to maybe give me 50watts plus per channel.

If I was to attempt this, I assume I would be better off with a "Kit" of some kind. Can anybody suggest a suitable manufacturer so I can start to browse.

Being a complete novice if you think this is a bad idea then please say so, as I would hate to buy, make a start and find it completely beyond my capability to complete the project.
 
Valve amps are a great way to start, since there's generally plenty of space inside and the parts are physically and electrically robust.

My only comment is that I'd seriously consider notstarting with an 845-based amp though - these run 800-1000v on HT supplies, just too damn dangerous for novice stuff IMO. I've built quite a few bits of kit one way or another and still wouldnt go there...
 
martin clark said:
My only comment is that I'd seriously consider notstarting with an 845-based amp though - these run 800-1000v on HT supplies, just too damn dangerous for novice stuff IMO. I've built quite a few bits of kit one way or another and still wouldnt go there...
Click to expand...

Lol, if Martin wouldn't go there then I'd certainly advise you not to!!!
 
Martin's advice echoed: I'm currently building a 2.4KV @ 1A DC power supply for amateur radio use and there's no second chance with that kinda voltage. I've been around HT since apprenticeship days and it's still a daunting task especially at switch-on time. Begin with a low voltage design for starters and work up to valve amps in time.
 
I wouldn't start with a valve amp if you're a novice.

If you make a mistake, you can end up with a very big bang ... or dead.

Even the low power SET amp I'm currently fixing (when the new transformer arrives), runs with 900VAC and 400VDC - which is serious stuff (and makes me nervous).

If you want to build something, and it needs to be powerful, a Class D kit (Hypex etc) might be the way to go. Even so you do need to be careful with the mains side. A Chipamp kit is another option.

Edit - or Les' 260 kit of course!
 
Why not try a World Audio one - i built a kt88 based one (kit88) with no experience and it was quite easy and did not go bang and responded well to 'audiophile' component upgrades.
 
Personally i would go with a Lm3886 based chipamp, a kit from chipamp.com would be a good starting place, or the My Ref C from http://www.twistedpearaudio.com.

First is easy and with good component get very decent results. Second is a little harder but not rocket science and gets amazing results, as someone else said Class d kits are also worth considering and the through holes stuff from 41hz.com is not too tough. Winding the inductors is a pain though i always found.

Phil
 
look at bottlehead.com for some nice US tube amp kits, reasonable price, good support, good directions, well liked, maybe some issue with getting UK power to work with them, but i do know some brits are using them.
 
Why not try a World Audio one
Click to expand...
Aha! Good suggestion. The company has been resurrected by Peter Comeau as World Designs (http://www.world-designs.co.uk/). Have a look at the WD88VA - seems in the right ballpark power-wise.

Rob Holt of this parish built the preceeding (near-identical) 6550-based poweramp as a novice - and I can confirm it sounds really, really good.
 
I would put an Avondale 260z on the top of my list of kit amps. Its a lovely fluid sounding amp with loads of detail and control. I'm about to convert an old Chrome bumper NAP250 to 260z spec.... Jon
 
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