My ACF pre.

What people are working on at the moment
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pre65
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#46

Post by pre65 »

Dave the bass wrote:Akido Cathode Follower I think Mike.

DTB
Correct. :)

Mike, I've only got the details on PDF, and I seem to have lost your e-mail address.

PM me with it and I'll send the circuit.
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#47

Post by simon »

Mike,

I'm on my phone so it's not easy to post links but if you google "tubecad Aikido cathode follower" I'm sure you'll get a number of helpful pages.
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#48

Post by pre65 »

Right ho, lets get this thing up and running.

Using my worst CD player, and a pair of the most crap car speakers ever made linked up to the 832a PP amp, it works ! :shock:

Even with the crap speakers it showed promise. :o

So now the baffles are plugged in, and it is good.

Next up is to put it in the system proper, and see what KT66 SET can do. If that works the might of 833a will be called upon. :wink:

I'll give it a play with lotsa different moooooooooooosic and report back later. :)
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#49

Post by Dave the bass »

Bet its crap really!

DTB
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#50

Post by pre65 »

Dave the bass wrote:Bet its crap really!

DTB
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#51

Post by pre65 »

So far.

I like it, but I would not say it's better than my best so far, ie the 26 pre.

Bear in mind this is a scratch build, using the proper PCB and/or different valves might make a difference.

I think anyone who definitely does not need gain will like it, but using less sensitive amps can show it up a bit in volume terms.

I'm not finished the discovery process yet, still got 811a and 833a to go.
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#52

Post by Ali Tait »

How does it compare to the Pre 3 Phil?
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#53

Post by pre65 »

Ali Tait wrote:How does it compare to the Pre 3 Phil?
Difficult to say at the moment Ali, cos my Pre3 has a fault and I've not used it for a while.

Must have another go at fixing it.
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#54

Post by Ali Tait »

Okeydokey. My kit should be shipped in a few days, he was waiting on the valve bases.
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#55

Post by Dave the bass »

Ali Tait wrote:.... he was waiting on the valve bases.
Thats clever, did he have both feet on one valve base or 1 under each foot?

Details!

DTB
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#56

Post by pre65 »

Dave the bass wrote:
Ali Tait wrote:.... he was waiting on the valve bases.
Thats clever, did he have both feet on one valve base or 1 under each foot?

Details!

DTB
No silly, the valve bases were at a restaurant. :wink:
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#57

Post by Ali Tait »

Dave the bass wrote:
Ali Tait wrote:.... he was waiting on the valve bases.
Thats clever, did he have both feet on one valve base or 1 under each foot?

Details!

DTB
No no silly, he has to stand on them to get them through the pcb!
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#58

Post by IslandPink »

pre65 wrote:I like it, but I would not say it's better than my best so far, ie the 26 pre.
Would you say there are any good or bad aspects to the sound, compared to the 26 ?

I have some ideas myself , but won't say for the moment !
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#59

Post by pre65 »

Hmmm.

Initially, with the 832a PP amp, I was quite impressed. It's got a sensitive input and only needed a 1/4 turn to be loud and powerful.

With the KT66 SET on the other hand the knob was nearly at maximum for some CDs, and seemed lacking a bit in scale, but good on more quiet vocal music.

With a powered pre like 26 or Pre3 everything sounded good.

But I've still to listen to 811a and 833a with the ACF so we'll see what happens tomorrow.
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#60

Post by IDM »

Hi Phil,

I guess from your initial listening comments that anyone with relatively insensitive power amplifiers might be better off with the full Aikido.

Also I had a quick look on tubecad and the schematic I saw had cathode bypass caps. I am sure that when I built a full Aikido years ago it didnt have any. Did you use cathode bypass?

Cheers
Ian
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