Ciscokid said:Hi,
Cool looking preamp. Where did you get the PCB for the rectifier?
ck
That came with the bridge. It is a Teac TP-S47-T and was something I just had laying around. It made layout simpliar that trying to use the supplied individual diodes. Worked well and it's quiet.
Variable mu valves
Remembering the way these valves were used:
The RF amp variable mu valves were only required to adjust the gain by a few dB or so, to avoid overload.
The main gain control was normally done in the first IF stage, by an EF183.
My point is, that it's probably a better choice than an EF183.
Also, I remember that before custom var-mu's, AGC was applied to valves like EF80's.
Cheers,
Nor am I, but I've seen it (and others) in use.EC8010 said:
I'm not quite sure what the variable-mu ECC189 is doing in your list,
Remembering the way these valves were used:
The RF amp variable mu valves were only required to adjust the gain by a few dB or so, to avoid overload.
The main gain control was normally done in the first IF stage, by an EF183.
My point is, that it's probably a better choice than an EF183.
Also, I remember that before custom var-mu's, AGC was applied to valves like EF80's.
Cheers,
beyond the bickering....
that is one fab looking foreplay! Verrrry nice.
...puts mine to shame. The top plate looks very
cooly minimalistic... just two glowing tubes.
makes me want to redo my Foreplay.
---------------------
don't get sentimental
it only ends up drivel
-------------------
that is one fab looking foreplay! Verrrry nice.
...puts mine to shame. The top plate looks very
cooly minimalistic... just two glowing tubes.
makes me want to redo my Foreplay.
---------------------
don't get sentimental
it only ends up drivel
-------------------
FU2.
Hi,
And am I the only one to spot the pair of clear top RCA 12AU7As or what?
No,I don't want do talk about zirconium getters...
Cheers,
Hi,
FU! I love 12AU7
And am I the only one to spot the pair of clear top RCA 12AU7As or what?
No,I don't want do talk about zirconium getters...
Cheers,
For what it's worth, a reply from another board:
The CV 4003 and the ECC82 are not the same. The ECC was manufactured specifically for audio application. This doesn't mean the CV 4003 is crap, just not manufactured to the same exacting standards that the ECC series. The CV 4003 is a "box plate" whereas the ECC series used "long plate" construction. The CV 491 from the late 50's is much better preferred to the CV 4003 and has "long plate" construction. The CV 4003 were manufactured from the early 60's into the 70's, the ECC began production in the 50's.
The CV 4003 and the ECC82 are not the same. The ECC was manufactured specifically for audio application. This doesn't mean the CV 4003 is crap, just not manufactured to the same exacting standards that the ECC series. The CV 4003 is a "box plate" whereas the ECC series used "long plate" construction. The CV 491 from the late 50's is much better preferred to the CV 4003 and has "long plate" construction. The CV 4003 were manufactured from the early 60's into the 70's, the ECC began production in the 50's.
12AU7A
Hi,
Yes,Sir..that's the ones.
I've never been too impressed with the Mullard range of ECC's boxed,long plate (and that's Philips for you and me).
Numero uno to me has always been TFK,than Philips and all its' subsidiaries.
If you need a list of those subsidiaries,I can provide it but it really goes global beyond anyone's imagination so expect an arm long of brands.
Cheers,
Hi,
You mean like these.
Yes,Sir..that's the ones.
The CV 4003 and the ECC82 are not the same.
I've never been too impressed with the Mullard range of ECC's boxed,long plate (and that's Philips for you and me).
Numero uno to me has always been TFK,than Philips and all its' subsidiaries.
If you need a list of those subsidiaries,I can provide it but it really goes global beyond anyone's imagination so expect an arm long of brands.
Cheers,
Probably wouldn't hurt to have some blocking resistors or something in here somewhere, but whatever.
Ah heck, it's too tight
- Not shown: a few Rs and Cs in series with the input to alter the F response. Bass is too boomy with my $30 RadioSnack headphones.
Tim
Ah heck, it's too tight
- Not shown: a few Rs and Cs in series with the input to alter the F response. Bass is too boomy with my $30 RadioSnack headphones.
Tim
Attachments
dhaen said:Hmm,
But, just because a valve was not designed for an audio application in the first place, does not necessarily mean it'll be no good for audio.
Cheers,
This of course is absolutely correct. My recent work tells me that the 6DN7 (line osc/output dual triode) should make (and apparently does make) a very good valve for audio.
Unfortunately ECC82/12AU7/5963/6198 etc, does not.
7N7
Wardsweb said:For what it's worth, a reply from another board:
The CV 4003 and the ECC82 are not the same. The ECC was manufactured specifically for audio application. This doesn't mean the CV 4003 is crap, just not manufactured to the same exacting standards that the ECC series.
This is not true.
CV4003 was made to very exacting standards; also known as Mullard's M8136, it was manufactured to meet a military specification. CV4xxx series valves are ruggedised and had to meet a number of stringent tests in this regard (cf the American "W" suffix). All the Mullard "M" series valves were special quality, which is why they received thier special nomenclature. Brimar's "T" ("trustworthy") range was another example of the same thing.
Your average ECC82/CV491 was turned out by the million, and was probably very good - within its metier, which was TV sets, instrumentation, guitar amplifiers etc.
Not in my amplifiers though (and neither is CV4003/M8136).
7N7
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