Employment offered; breadboarding a Tube Monoblock

[gypsielectro]

I: have a *workable* schematic; the tubes, transformers, and $$

You: have the time and experience to breadboard together a working prototype Monoblock Single-Ended Class A Amp

I'm looking for a quote; more details will be provided by request

Suggest: 50% payment on acceptance of your quote with balance of 50% paid on completion of the project

*Humor me; I have $$ to spend but v. little time + zero experience

Post here to followup, or email me: gware@eudoramail.com

I'll reply to all emails and followup postings here

Graham Ware

[Audio_idiot]

Hi,
A show of your "workable circuit" will be helpful.

Cheers

[gypsielectro]

These are *similar* to 6384 Bendix tubes, which in turn are part of the 6AR6/6L6 family

Jean-Paul has archived a link to a basic circuit here: ( which does not include a power supply )

http://www.diyaudio.com/forums/attac...amp=1047252197

and there is an archived post for an Amp using the 6384 Bendix tubes here

http://www.the-planet.org/audio.html

courtesy: Gary Kaufman

I would stress; I am *NOT* attempting this as a commercial undertaking; this is strictly an Amp for my own use and enjoyment
*If Gary us unhappy with me posting the link; I will request a moderator remove it*

The specifications of the 6889 are here: ( warning, it's a PDF file )

http://datasheets.electron-tube.net/...131/6/6889.pdf

The 6384 is a very similar tube; but does not use a cap on top of the tube which the 6889 does; specification of the 6384 is here: ( warning, its a PDF file )

http://datasheets.electron-tube.net/...131/6/6384.pdf

I've been recommended to use 5K transformers for single ended Class A type Amp: and already have a Pair of Transcendars ( www.transcendar.com ) their Part number

TT-016-OT

I have 16 ohm Speakers which are v. efficient and the Amp only needs to make 1-2 Watts, I would prefer 2 x Monoblocks as opposed to 1 x stereo chassis

I have another 6384 schematic from a Japanese magazine I would have to scan and upload

I'm hoping that I can find someone to breadboard together a single working Monoblock; I will then construct a chassis based on that

Kind of like this:

http://wavebourn.com/images/4101/4101-maket.jpg

but I'm keeping an open mind and I'm open to suggestions

Best!
Graham

[Bandersnatch]

Hey-Hey!!!,
Seems a waste to run the 6889 as a triode. Any special reason not to pick a triode instead?

If you must go ahead, what you propose is a week's work. It is going to take an undetermined amount of time *more* than a week depending on how complete your parts shopping has been, and what you want that isn't there already.

How complete should this breadboard project be? Here you have left a lot to assume( as I did above ). If you want it working, on a board, that's one thing. If you want a it attached to a plate you can drop into a base, that goes a bit farther than breadboarding( and the 1 week estimate ).
cheers,
Douglas

[gypsielectro]

OK, a week narrows the parameters down; let's argue that a Tech with the Right Stuff, working at a reasonably unpressured pace ( maybe in their own time ) is worth US$25.00 an hour, with a week ( 40 hours ) achieving results

Say; US$1,000 worth of labor

*Plus parts*

My expectation would be to be delivered the basis of a running, reliable, stable Amp; but not Rocket Science or miracles

Say we spread that 40 hours over 8-10 weeks to allow for accumulation of Parts, assembly and testing, you can set your own pace

*Price of parts is not included
*US$1,000 is the budget for labor ( max. )
* 10 weeks is the turnaround ( max. )

Could a single, simple, working Monoblock with a temporary base of say: *1/16th inch plywood/plastic/scrap * be assembled + tested within that timeframe?

And within that budget?

IE, not a completed, plug and play showpiece exhibit; but *definitely* a prototype that had been assembled and tested

Suggest: I could use the 1st chassis as the basis for assembling a second Monoblock myself

+�@I could make a chassis out of something other than scrap at my own pace thereafter

Again; nothing is "carved in stone"

In the last 12 months I've had a Phono stage built for me using a DACT board ( Singapore ) and a turntable power supply built from scratch, ( Australia ) both successful one-off projects

What I am proposing *May* be realistic or unrealistic; feel free to comment!

And OK, maybe this goes *beyond* breadboarding....

GW

[garbage]

how abt monos that look like these:

[audiovista]

"...What I am proposing *May* be realistic or unrealistic; feel free to comment!..."

Graham,

I'd say that your budget for labor and time seems reasonable. Same for the expectations as to what you should get in the end.

Boris

[gypsielectro]

Originally posted by audiovista
"...What I am proposing *May* be realistic or unrealistic; feel free to comment!..."

Graham,

I'd say that your budget for labor and time seems reasonable. Same for the expectations as to what you should get in the end.

Boris

Boris,
OK, then it looks like I'm on track, anyone want to out their hand up and take the job?

GW

[Bandersnatch]

Hey-Hey!!!,
I would consider it, but I have to finish this one first!

http://www.audiokarma.org/forums/sho...d.php?t=105378

This one is a cross between presentable and breadboard. It will eventually get another output TX and 813 finals....
cheers,
Douglas

[gypsielectro]

Originally posted by Bandersnatch
Hey-Hey!!!,
I would consider it, but I have to finish this one first!

http://www.audiokarma.org/forums/sho...d.php?t=105378

This one is a cross between presentable and breadboard. It will eventually get another output TX and 813 finals....
cheers,
Douglas

That's a great looking Amp and many thanks for your feedback and input;


I've accepted an Offer today from a DIYAudio guy in the Netherlands who is just starting his own tube Amp business

I'll post the results up here in a few weeks when we're done

Thanks to all who have contributed ideas!

Graham Ware