valve amp guinea pigs needed

bottleneck

bottleneck

talks a load of rubbish
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Hi All,

Along with some pretty serious mates - like people from Prometheus Audio, former World Audio/ Audionote/ Marshall Amplification staff...

I have, after 2 years, got a prototype amp up and running.

Really, the goal was to 'kick the shit' out of entry level valve amps.... :D

So we have, I'm proud to say -

* Valve Rectified , Choke Power supply (like a Border Patrol)
* Interstage Transformers, instead of capacitor coupling (again like Border Patrol)
* Transformers made specifically for UK voltages (makes a difference to the sound quality), and specifically for the amp. You can't buy these puppies.
* my favourite, the EL84 - meaning revalving the power stage can be done for about £30 !

...hows that for a ''my first valve amp'' ??!

One of the reasons it took so long to make - hum, and hiss - the enemies of the valve amp ; we wanted to keep the sound quality at a really high level, but have background levels of noise at very, very low levels.

I've got it now running high into a pair of 115db JBL horn tweeters, and it's REALLY quiet.. quieter than 3 solid state amps I've tried, and my other valve amp, which is a quiet one anyway.

Basically, we designed this (great sounding but visually slightly challenged) amplifier to be available as a finished amp for about £700, and a kit for about £500.

I can't think of anything with this kind of specification for that kind of money.

I already know it kicks the arse of some of my favourite budget champions (won't mention names)... but how does it stack up against the best EL84 amps out there? ... A Shindo Monbrisson? A Leben?

Frankly, if it doesn't hold it's own. . . a prototype it will remain. . I've got no wish to bring out a ''me too''...

So have we done it?
Dunno!

I have a mate (Tom, you've been volunteered!) with Tannoy GRFs, another mate with £20,000 horns.

I want people who really know valve amps, and have top of the range ones... - and live near Reading to give me their opinion... if they'd be so williing?

I hope that doesnt sound snobby or elitist - I want to set a high bar.



Anyone fit the bill and able to help?

Please send me a PM if you can . . .


I got into this because I wanted to ''give something back'' to PFM, Zerogain and a hobby that has helped me so much over the years. If I launch this thing - I would need to sell 15 of them a week !!!!!!!! in order to get the kind of living I get now, and Im no Doctor... so please don't think this is a profit venture...

...no, it's ''can we make something better than whats out there now for less money''? - I may have proved that you can, if you sacrifice most of your profit, or I may have failed altogether..

I need some PFM/ZG feedback,,... so now over to you guys..

Oh yes, my baby is under 15w, so valve friendly systems please . . !

Thanks one and all. :)
 
Very interesting, Chris, and I love the EL84, too.

bottleneck said:
I already know it kicks the arse of some of my favourite budget champions (won't mention names)... but how does it stack up against the best EL84 amps out there? ... A Shindo Monbrisson? A Leben?
Click to expand...

The Shindo Monbrison is a preamp. The Shindo EL84 is the Montille, and I happen to have one here. I don't live near Reading, unfortunately.
 
Hi Chris,

This sounds interesting.

I would like to help out having heard, used and owned many valve amps. Downside is that I don't live near Reading.

It does good for £700. There isn't much competition at that price.

The Puresound A10 @ £599 springs to mind. It's a nice sounding amp but I can hear it's limitations.

pure_sound__a10_front_2.jpg


Good luck with the venture.

SCIDB
 
Hi Dean

Thanks for the kind words.

Basically it came about because I couldn't get what I wanted for the kind of budget I wanted to pay.

I wanted Interstage transformers, Choke & valve rectified power supply, a cheap re-valve every couple of years, hard wired for easy repair and build changes, good quality of components (it will be entry level mundorf, audionote caps, that kind of thing).. for the money I wanted to pay.

I see it as a grown up Leak Stereo 20 if anything.. but in kit form.
 
Hi Chris,

Will this be made abroad? Any pictures?

Not sure what sort of quantities valve kits will sell but 780 a year seems a big target.

SCIDB
 
Hi Dean!

The Transformers are made for us by Prometheus Audio. Assembled in the UK by a valve tech I know.

LOl, don't think I'll sell 50 a year, nevermind 780 !

It's not something I'm doing for a salary. If its deemed to be as good as I hope, it will be launched as a 'hobby business' for me, it may pay for a holiday at best I would think...

Equally, if it's not shooting way above it's price mark, it will never see light of day. Wouldn't personally see the point..
 
Hi Chris,

I hope it does well for you. It does sound that you get a lot for the money. Starting as a hobby is always a good way to go.

SCIDB
 
Good luck with it Chris.

The only advice i would give is to reconsider the grouping you are targeting for the auditioning. I'd widen it - a good amp is a good amp so it should delight anyone using it within the limited power envelope. if you are vetting the users, probably best to ensure their speakers are broadly compatible.
 
Good luck Chris

When you have the aesthetics sorted out, I would be eager to try out with my small Shahinians with a view to a future purchase. BTW I'm also in Reading and used to be associated with Concordant Audio when Doug Dunlop was alive...just reminded myself that I still have his hand drawn circuit diagrams somewhere in the attic.

Rana
 
I'm running opera conconance ....cyber 800

if they fit the package ....then I'd be interested ...though live a little beyond your catchment area ...but will travel !

and I do have time on my side ...

you can pm if I fit the bill
 
I've just bought an EL84 VLL 2000 from Montesquieu (list £600) designed by David Wright (now overseeing BorderPatrol). 12 Watts push pull. Picking it up this week in Winnersh. Could come straight over with it..happy for you to knock it over with your new
amp..love to have a listen anyway.
 
Chris came over today

System: Technics Sp10 slatebed, gunmetal armboard, Acos Pioneer PL-71 arm, ortofon SPU Royal N, Lundahl 1681 Step-up, Dynavector P75 Phonostage, prometheus TVC, amp, then Tannoy 15" HPD rect. GRFs.

Great afternoon: Really interesting to hear another valve amp on my system.
My DIY SoH amp uses Lundahl output transformers and a 12.5kg beast of a mains transformer not commercially available. Lundahl do something that could replace it should it ever fail but it would need two of them one for each channel!
A mate of mine was over who also built a SoH amp and he has since built a Mullard circuit EL34 amp as a reserve - The SoH is the first choice though.

We spent about 50mins listening to various stuff on my amp first.
We got though tracks from the following on vinyl.
Tori Amos - Boys for Pele
Hotel California -Eagles
Prince (something or other that my mate brought over) sh!te recording or pressing or something...
Louis Armstrong and Duke Ellington - Together
Somthin' else - Cannonball Adderley
Milcho Leviev - Blues for a Fisherman
Nick Drake - Five leaves left
Others? Can't remember

Then we connected up the Bottleneck special.

Immediate impression was that it was a little bassier (perhaps I gave it more welly to start with) and not so airy / etched / detailed in the top end - then it started to warm up more and more and we started to get used to it.
It was tonally different and I gave it the Tannoys a tweak (+1 level on the treble energy) to get to my usual listening balance / zone.

That done and after an hour we forgot about the amp and were listening to the music... Did the same selection as above to try out various sounds.
Man does the clarinet / cornet on that Together 200g album sing or what.
we also tried Kate Bush - little minx that she is...

So to sum up the Bottleneck amp then: It's really rather good. At the price point it's excellent.
What could you get for £500-£700? Perhaps another valve kit or something SS by Arcam or Marantz - I am sure it punches well above those weights.
Runs much cooler than my amp, was really quiet hum/hiss wise, no power on off crumps or cracks. Just easy to use.
Power tube rolling - no problem at a fraction of the KT88's.
I liked the fit and finish of the case too and connections round the back.
 
whoops

I guess I was too busy having fun listening to music !.. (I should take this more seriously..)

You know, anyone looking for some seriously good speakers for beer money could do a lot worse than send Steve a PM.

A pair of GRFs for less than £2k including drivers , wood, crossovers etc is outrageously good value.

Steve did mention that he is selling his own pair (in his pic) as he fancies some with a slightly different front baffle.

Dev - you should pop round !!! ... raid the piggy bank !!
 

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