Darren 212 / 833 SE amp

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Andrew
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#91

Post by Andrew »

Well, with a 10 Amp MOSFET you could probably use clip leads - if that helps :wink:

-- Andrew
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Paul Barker
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#92

Post by Paul Barker »

here is a simple one but don't use 24v zenner strt with 5v (AOT) and parallel power transistors to cope with greater current . (3?)

so you are maing +5v 10a reg and -5v 10 amp reg

sort of like the chimera labs 211 filament supply.

http://sound.westhost.com/project102.htm
Darren
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#93

Post by Darren »

One problem with weird valves as we all know is sockets..!!

So I decided to make my own. machined from leaded brass these will also act as radiators to help cool the valves. It will also offer some protection for the cables as well. Each one has a 6mm thread in the end for mounting and connecting the cabling.

I will make some "Top Hats" in PTFE to mount them to the chassis via the 6mm bolts.

Image

I will prob mount them upside down to keep the HT at the bottom. Be a bit safer. Not much but a little.

Nice shinny bits for the kids.... :D
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Nick
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#94

Post by Nick »

Very nice. I NEED to get a lathe one day.

Mind you, I NEED a Tek 7 series mainframe scope, and so on.
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Paul Barker
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#95

Post by Paul Barker »

If that was done with a parting tool, well done. The end result makes it look easy, but it isn't is it?
Darren
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#96

Post by Darren »

Yes it was and no it's not....!!!

I "NEED" a bigger lathe....!! Took me about an hour to make each one.


Out of interest I measured the temp of the valves last night, 1100v, 140ma each about 75W. Temp on the glass was 175 deg C on the one without caps and 155 with. So around 20 deg drop.

It's mostly to protect the lead sealed connectors and glass seal.
Originally I mounted one valve by drilling two holes in a piece of MDF and inserting the pins in this. They are now well charred..!
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Paul Barker
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#97

Post by Paul Barker »

Yes you have to watch the connections in these hot valves. I had the top pip on a 572b unsolder itself. The music started to sound intermittently odd, on investigation the shunt regulator was coming in and out as the contact became increasingly and less resistive due to molten lead.

All these people who just study the net and think they can build any amp they like from head knowledge have some interesting discoveries down the line, if they ever put solder to copper (which they probably won't, because they will be too busy sounding forth their expertise on the net). I should keep my trap shut and let them fail all on their own, and find out for themselves the reason real life is different to the net.
Darren
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#98

Post by Darren »

I've had a bit of time to listen to the 833s recently and had a couple of mates mesmerised which is always a lift.

I may have mentioned I have taken my active crossover, ss amp and 15" bass driver out of the system. I'm now finding the bass gels better with the rest regarding timing and pace.

Another really strange sensation is bass notes that you can "feel" but not hear. Now that's a really odd feeling. It's as large as life but you can't hear it at all. Doesn't happen very often, just the odd note or two in some recordings. But it gets me every time it happens.

Reminds me of the first time I flew in a Cessna, watching the moment the wheel left the ground and witnessing the gap. Very odd sensation, hard to describe. Certainly not normal and that odd bass note is very similar.
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Greg
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#99

Post by Greg »

Not wanting to gloat, but that is my home experience anyway, even with a 300B PP clone kit amp coupled to KLS3's. It's this kind of thing that now makes me very jaundiced about eggfests etc. At home the system sounds very good and properly extended right down to feeling the low frequency's we don't hear. Therefore I'm a bit sceptical that all this valve chasing really is worthwhile. I'd love someone to put a new amp in my listening room that would blow me away and rubbish what I have but I'm even further sceptical that this will ever happen.
Getting together is good fun but (IMHO) we're not going to hear anyrthing that good unless it's something like Paul's demonstration of a 612 a few years back. To be totally frank, this time Nick's offerings were not a patch on his previous 611 stuff especially without his phono stage. I know the WD forum spouts positives about sounds heard but sorry, that didn't happen for me. Generally I thought what we heard was very average and generally poor. I understand Steve's limitations and also take into account the listening room effects and realistically my applause for Steve's system was much to do with the best sound of the day rather than simply a good and creditable sound I could aspire to. Frankly the whole weekend produced nothing good for me apart from Will's system that sounded great on Sunday albeit with some of the most simplistic music imaginable.

I now understand why the likes of Richard do not attend these events. They know they are not going to hear something better than they already have at home. Having said that, he/they miss out on the comraderie.......and actually the beer et al was very fine!
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#100

Post by Darren »

Hi Greg,
I think I understand what you mean, feeling bass, but this is very very different. Not something easy to explain and certainly not something I've heard before anywhere.
You can feel a lot of bass, but what I'm now experiencing is a real "thump" that is very new to me and I've tried plenty of setups before this.
The high powered SS fed sub 44hz didn't do it.

When I have my new house setup it would be nice to have a few of us to get together in the Welsh hills. There will be plenty of room to stay over.
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Nick
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#101

Post by Nick »

Err, Greg, I think your logic is a tad unbalanced.

Ok, your kit sounds better in your home that anything you heard in Doncaster. Ok, thats more than beliveable. But you then compaire that to other kit, not in its home, and then infer froim that that your kit at home will sound better. There is a logical gap in that point.

The only solution as Darren said, is to hear all our kit in our own homes. Obviously thats a bit of a problem.

But without hearing your own kit also out of its home environment its impossible (IMHO) to say either way.

In reality, the reason I don't bring the 211 out anymore is its hard work, and I have got fed up of building kit with the goal of hearing it in a big room, I don't live in a big room, and I don't build stuff now to impress others at get togethers. At the moment the 300b is more practical, and for my ears sounds better at home than the 211 in most of the ways I find important, thats why I am using that now, not to gain points at an open day.

Its much more about the social aspect for me.
Cressy Snr
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#102

Post by Cressy Snr »

Personally I love these get-togethers and learn a lot from them. A direct result of these fests is that I invariably find a way to improve on the sound quality I get in the home.

The appalling performance of the Metronomes led me to have a serious rethink about the way they operated at home. This resulted in the sub being ditched, the design of the speaker being altered to provide a base plate for the port output to reflect off into the room. Without the fest I would still be ploughing along with the sub, none the wiser.

The social aspect is great and it is nice to see what other people are doing. The thing is not a contest about who has the biggest, bestest most spectacular kit . Nor is it a sound quality thing. Flea powered amps and big rooms don't mix anyway.

Valve DIY is a great hobby and a complete rejection of consumer hi-fi and all the rip off crap that goes with it.

Personally I couldn't give a monkeys how my system performs or not on complex music. My own reference point as I talked about with Ed at Steve's place is 60s soul and Motown. Outwardly simple basic music but horrendously difficult to reproduce properly.

You need a system that will kick out a tight rhythm like Naim kit does so successfully. At the same time it must dig deep to ferret out the detail of the performance, the interplay of the musicians, the count ins, the whoops, yeah's and "hit it baby"s in the far corners of the soundstage.

The slightest upper bass forwardness leads to soggy one note noise that destroys any reason for thinking that James Jamerson was one of the greatest bass players who ever lived. Poor old Duck Dunn sounds like an amateur too.

The presence region must be well- balanced. The merest hint of forwardness and you will end up with hideous nasal screech from female vocalists and ear bending shout from male high tenor voices. You can forget any hint of the subtleties of Steve Cropper's guitar playing, King Curtis's tenor or Junior Walker's alto saxophones, they will just irritate.

I'm afraid if your system can't play Dusty, The Supremes, Otis, The Funk Brothers or the Stax house band without them taking your head off then it is not doing its job...end of story, no arguing. Mine still doesn't quite pull it off on one or two records but the better I get it the more stuff from this canon I can play and the more jazz, blues, folk, rock and pop too. The quest therefore goes on.

Get the soul genre right on your system and you can bet that the complex stuff will work too.

Steve
Last edited by Cressy Snr on Tue Jun 26, 2007 8:34 pm, edited 1 time in total.
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ed
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#103

Post by ed »

Personally I couldn't give a monkeys how my system performs or not on complex music. My own reference point as I talked about with Ed at Steve's place is 60s soul and Motown. Outwardly simple basic music but horrendously difficult to reproduce properly.
fwiw Steve I think your stuff is as complex and layered as almost anything I can think of...IMO a lot has to do with mixing in the brass which has a very dominant attitude...very pushy stuff, brass!!

a noble quest if you ask me

Ed
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Paul Barker
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#104

Post by Paul Barker »

I found you an on off switch for your 833 amp Darren. Just need the lads from alf veet azaine pet to go over there and dismantly it and bring it back to North Wales via Middlesborough.
Darren
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#105

Post by Darren »

Sounds interesting, any further details?
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