Audio Project Amplifier Speaker Loudspeaker Kit
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Pics of Foreplay Preamp - Click HERE for Original Thread
TubeHound
Hi,

Finished a BottledHead Foreplay preamp and used all the standard kit parts for the inside ,(not outside). It sounds ok, as I think the tubes that came with it are not top notch. I have ordered some mullard 12au7's to try out. I imagine there is some break in period, but I do not know much about that.
Ciscokid
Very nice matching set.. ;) I have read that the Foreplay needs a certain amount of break in time.. I wouldn't think that it would be that long.... You might want to ask that on the Bottlehead fourm..

ck
Bolivar
GORGEOUS!

I hope that it does burn in to your liking. And like you say, maybe a different set of tubes.
slowmotion
Man , do they look good! :cool:
JBL
That's a cool looking diy pre-amp!
cowanrg
ABSOLUTELY, 100% POSITIVELY GORGEOUS!

wow. im impressed. i love the copper and dark wood approach. looks killer!
Ryder
quote:
It sounds ok

that is luke warm if you ask me.
what are you comparing it to?
You are running it with your JElabs 300bs if I remember right?

Cheers
Craig Ryder
Lisandro_P
OH-MY-GOD! :bawling:

I want one so bad...
TubeHound
quote:
Originally posted by Ryder


that is luke warm if you ask me.
what are you comparing it to?
You are running it with your JElabs 300bs if I remember right?


I did have the CDP hooked directly to the JE amps and after adding the preamp, the music seemed to loose some detail and focus. It is sounding a little better right now and I hope it will age well.
fdegrove
Hi Paul,

First of all congrats on another marvelous piece of art....you have once again created one of those DIY jobs that don't look at all DIY.

Adding another stage into the chain is likely to have a detrimental effect on the sound,no matter how good it is....

Have you looked at phase inversal by the preamp?

That may well be the culpritt of what you observe.

Cheers,;)
planet10
Paul,

Did you add the optional CCS to your Foreplay? I understand this makes a huge difference -- as it does on most CF stages.

dave
fdegrove
Hi,
quote:
I understand this makes a huge difference -- as it does on most CF stages.

IME it would be safe to say it will have a major impact on any stage/topology...not just CFs.

Ciao,;)
TubeHound
To all who have responded, Thank you!
quote:
Adding another stage into the chain is likely to have a detrimental effect on the sound,no matter how good it is....

HI Frank,

This did cross my mind, adding more resitors, caps, ect to the signal.
quote:
Did you add the optional CCS to your Foreplay? I understand this makes a huge difference -- as it does on most CF stages.

Hi Dave,

Not yet, I do have this 'upgrade' , but did not install it yet. I want to listen to the preamp for a while, then add this. To see if I can hear a difference.

By the way, my next project is speakers, DIY of course. Would you have any recommendations for me to look at?
fdegrove
Hi Paul,

If you allow me....
quote:
Not yet, I do have this 'upgrade' , but did not install it yet. I want to listen to the preamp for a while, then add this. To see if I can hear a difference.

You're in for a pleasant surprise there...you're adhering to a wise policy though,better get acquainted with the circuit first.

As for speakers,well that is of course Daves' department...I'd be looking at a FR 94dB+ or similar arrangement.

Happy building,;)
planet10
quote:
Originally posted by maybeim
By the way, my next project is speakers, DIY of course. Would you have any recommendations for me to look at?

What kind of amps are those that we see the edges of?

There are many potential speaker projects... what kinds of things have you had your eye one?

I'll ask some more questions as we go along (and probably split this off to the Loudspeaker forum once we have a couple posts happenin')

dave
Maxwell
Hi Paul
Lovely job on the pre-amp, and the amps. Your earlier thread on the power amp construction inspired me to start chassis building, but that's another story.
I have played a little with different 12au7, although in my case they are drivers for 300B not preamp. I found that the late production Mullard (70s & 80s) were a bit ordinary, although perfectly good.
Early Mullards are better, but the best I have tried were Amperex Bugle Boys.
pedroskova
The changes that the C4S's bring to the Foreplay are not subtle. Some, who get used to the rather lush character of the stock unit have a hard time getting used to the changes - but most are running it into SS amps.

Paul Joppa calculated the operating points for a number of different tubes with that circuit at the following post...

http://www.AudioAsylum.com/forums/b...ages/21342.html

You'll need a beefier tranny for most(or a separate filament tranny).

Auricaps for the output caps also offer alotta bang for the buck.

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