DIY valve amp for my Horns. Suggestions?

Hi guys,

I think I got the bug . I'm currently working on a pair of DIY horn speakers. I don't think I'm too far from being ready to give them the very first audition. Exciting.

http://www.vinylengine.com/phpBB2/viewtopic.php?t=27670&highlight=

As they're very sensitive, they are the perfect excuse for... building a valve amp. Wait 'til she knows... Mmm. You had a hidden agenda, didn't ya?

I'm thinking single-ended topography here, very simple lay-out with only a few components (I am a complete newbie, though I own a soldering iron). I believe 5 watts of triode power would suffice, even less.

Any ideas, links, experiences, pictures, schematics and suggestions are wholeheartedly encouraged. I've been surfin', but feel a bit lost and overwhelmed and need some guidance here.

My dream? Well, an entire VincAudio system. The sky's the limit. I'm just having so much fun with this DIY thing.

Regards,

Vincula
_________________

 

If it were me Id definitely look at the Glasshouse 300b,superb amp and not too difficult to build, looks the part as well.

 

WOW, those Glasshouse kits do look scrumptious! I'm pretty sure they sound lovely and are relatively easy to put together... for someone with a bit of experience, though. I admire Audio Note gear (have a pair of AZ-Two's myself), so you just hit the right button.

I was thinking of a more "humble" start, maybe something based around a 6V6, an EL84, a 2A3 for instance, who knows, with a very minimal circuit. The idea I've got of a Decware Zen amp or something like that, but built from scratch. I've been having a look at BlueBell Audio as well. Any experience with those? There seem to be so many around...

Thanks in advance for all the guidance. I've already put Glasshouse under faves!

Regards,

Vincula

 

Dont know Bluebell Audio, DIY HIFI is worth a visit ,Audionote do some nice kits as well but to be honest off all the kits , which isnt many, I have built Glasshouse was leagues ahead. World Audio design, or buy a completed kit and tweak it to get a feel for diy. Te Glaashouse has very straight forward instructions , Bottlehead is another good start.
http://www.diyhifisupply.com/

http://www.bottlehead.com/

 

Thanks for the tips, mate. Gonna put myself to do a bit of web research, then.

Regards,

Vincula

 

Hi Vinc

I know nick at hifi collective very well.

Due to the unexplicably weird and strange fact that of the 20 or so 300B's he made kits to build, they actually sold very slowly.

So much so, that I believe now that there is only 1 (or maybe none) left, he has no intention (last time I spoke to him) of repeating another run of amps.

A terrible shame in my opinion - a better kit for the money I have yet to hear.

The last possible remaining one may be gone, may be still there. If you want it, raid the bank and buy it fast.


Long term if you wont be buying soon, DIY hifi supply make some nice kits.

 

Vinc.. just to mention.. I recently built a prototype EL84 amp - valve rectified, choke power supply, interstage transformers. A better EL84 amp I haven't heard at the kind of money it was made for..

.. but Nicks 300B amp is a better amp. It's a better tube (the 300b). It's got bigger transformers (audionote transformers I believe). It's only about £200 more than a world audio EL84 amp, which is a mile behind what I made (in my view).

Can't reccomend this last, great amp highy enough. I can't believe he's not going to make more of them.. I'm really sad about it

 

I'm talking to Bluebellaudio in Scotland.

http://www.bluebellaudio.com/

He recommends me to build a 2A3 SE direct-coupled triode amp. I'm leaning towards this in one box, stereo amp+pre, to cut clutter. Just got a Rega RB300/AN II arm (silver wired version) off him and he seems to know his bit. Would need more expensive output trannies for a SE 300b, though I like it too.

What to do? Build more than one, I s'ppose!

One thing is clear: I'm taking the Single Ended triode fleawatt approach.

Regards,

Vincula

 

yeah, the glasshouse 300b can also be configured for 2a3.

I think single ended 300b or 2a3 is definately a great way to go - as long as the circuit, transformers etc are good.

Nothing wrong with building a decent passive pot into the amp either.

I'd make sure whatever kit you get it has (apart from the above) lots of room inside to make future changes. I think this is important when you want to play upgrades etc.

Have fun with it

 

Hi Vinc

Which amp at bluebell were you thinking of buying?

All the best

Cheers
Chris

 

Hi Chris,

Look on the website under "ENCLOSURES", then click on "chassis examples". There are some lovely amps there, especially a red 2A3 direct-coupled SE monoblock. I'm considering building that one into one case, after talking to him. Many temping ones there though. See this one on Big Ears Audio:

http://cgi.ebay.es/ws/eBayISAPI.dll?ViewItem&item=270519045484&ssPageName=STRK:MEWAX:IT

Just call him up. A great Scotsman living in St. Andrews. He'd love to chat with you. Tell him about Tomás from Spain. He will know about the project. He restores Garrards and many more things, at least until his family kicks him out of the house.

I can recognise myself there too!

Regards,

Vincula

 

I agree totally. The Glasshouse is a very special amp, and deserves to be better known. I've had mine for over 4 years now- still on it's original 300b's too, and fully intend to keep it for ever. It's my perfect amp, the fact that I built it is the icing on the cake=) Adding a good sprinkling of blackgates, AN pio caps and tant resistors just let her sing even more beautifully.

That there won't be anymore of them is sad. I'm sure all the current owners will be treasuring theirs as I treasure mine.

 

Kit building

Hope I'm not speaking out of turn here but I am just a little bit concerned about the newbie quote and "have a soldering iron" statement.
Having seen the results that it is possible to get with a soldering iron in the hands of someone not experienced in their use you could at best waste your kit money and at worst do yourself some damage with the voltages present in a valve circuit.
My advice would be to purchase some odd pieces of tagboard,some perforated copper stripboard,a small reel of 21SWG bare tinned copper wire and some plastic sleeving.Practice making good joints on the tagboard and copper stripboard with the wire, at first without the sleeving present and then with the sleeving up to the joint.When you can make a good quick(i.e.without the plastic sleeving melting back up the wire) clean joint that has a good fillet of shiny ( not crystalline ) solder around it, you are in a position to start on a kit.
It might cost a few pounds but better in my opinion to spend it on the above than build a kit that could be a source of continued trouble and potential hazard.

 

Sound advice. I'm actually practising that. How to get a nice joint :MILD:.

Well, the experts here guided me to do as you say, so yes, rather spend a few quids on experiments than risk my own life in the attemp of achieving the goal too quickly. No rush then.

Fortunately I've got a Croft pre and a friend's gonna loan me his Croft Amp -one of the very old ones! A real peach!- on a long-time basis. He had it recapped recently, and he prefers his Leak amps -I don't, so I'm a happy bunny.

Gonna concentrate on finishing the horns and tweaking a couple of decks I've got lying around here for lazy audiophiles and music lovers.

Thanks for all the feedback mates

Regards,

Vincula