| Wardsweb |
| Hello all, just found this board. So I thought I would show you my latest projects; Custom Bottlehead Foreplay. |
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| Wardsweb |
| A picture from the reverse side. |
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| Wardsweb |
| The layout is true to the schematic but not like you would build if you used the supplied directions in the kit. |
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| Wardsweb |
| The only mod was the use of some Gudeman caps in the outputs. |
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| EC8010 |
| It's very pretty - so, was it worth the trouble? |
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| Wardsweb |
| quote: | Originally posted by EC8010
It's very pretty - so, was it worth the trouble? |
I wouldn't call it trouble, because I like building things. I'm a tinkerer at heart. This is the first tube anything I've ever built, so not much to compare too. I like it and it works well with my Altec A7's. Building some Paramours now to go with it. |
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| Joel |
Holy smokes... nice wiring job!
I want to throw all my amps in the garbage now. Thanks.:bawling:
I have the same speakers. They're heaven on earth.:angel: |
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| harvardian |
Hi,
Do you want some C4s's. I have a foreplay that is collecting dust.
Beautiful!
Dale
P.S. I also have some NOS Mullard tubes... |
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| Wardsweb |
| quote: | Originally posted by harvardian
Hi,
Do you want some C4s's. I have a foreplay that is collecting dust.
Beautiful!
Dale
P.S. I also have some NOS Mullard tubes... |
Thanks for the offer of the C4S, but I already have some. So, which Mullards do you have? |
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| harvardian |
From upscaleaudio
Here is his description:
12AU7/ECC82 CV4003 Mullard. HEAVEN!!!! Attn: Rogue and Conrad Johnson owners and those with other "picky" preamps!! I had about enough of the PV-10, 11, and 12 being a bit tough on 12AU7s, and was suggesting folks stay with Chinese or RFT even though they don't sound as good as a Mullard. We now have a test where we can supply you with premium tubes that are quiet and don't go microphonic.
The Mullard CV4003 is a wonderful tube British tube with the midrange we crave. For premium select $35. For Private Reserve $40. For Rogue/CJ owners, we have a special test that only 5 out of 100 will pass. $45 each, but you won't have any more problems, so it's worth it.
I have the $40 ea type. |
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| dhaen |
Looks pretty, and nice:)
Do I see a small PCB towards the back?
Cheers, |
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| EC8010 |
| quote: | Originally posted by harvardian
From upscaleaudio
Here is his description:
12AU7/ECC82 CV4003 Mullard. HEAVEN!!!! Attn: Rogue and Conrad Johnson owners and those with other "picky" preamps!! I had about enough of the PV-10, 11, and 12 being a bit tough on 12AU7s, and was suggesting folks stay with Chinese or RFT even though they don't sound as good as a Mullard. We now have a test where we can supply you with premium tubes that are quiet and don't go microphonic.
The Mullard CV4003 is a wonderful tube British tube with the midrange we crave. For premium select $35. For Private Reserve $40. For Rogue/CJ owners, we have a special test that only 5 out of 100 will pass. $45 each, but you won't have any more problems, so it's worth it.
I have the $40 ea type. |
What is this nonsense? The Mullard ECC82 is a field scan valve (an application that does not require low distortion. The one remarkable feature about this valve is its consistency between manufacturers and samples. Selection is not necessary. They are all equally poor for audio. |
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| fdegrove |
Hi,
| quote: | | They are all equally poor for audio. |
He,he...and if you really want to listen to the worst of this kind try the nickel plated 6189 as was used by the French postal services and usually made by Cifte...yuk.
Instead of spending money on so called premium 12AU7A/ECC82s it would be much better to mod the preamp and use a similar gain valve such as the 6CG7/6FQ7 or better still a 12BH7A.
Cheers,;) |
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| dhaen |
Hmm,
It may well be the case about the ECC82.
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, |
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| fdegrove |
Hi,
| quote: | | 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. |
Not all that many tubes were designed with audio use in mind anyway.
And amongst those that weren't designed with this particular use in mind, there are a lot of various types out there that all sound a lot better than an ECC82.
Cheers,;) |
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| EC8010 |
| quote: | Originally posted by dhaen
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. |
I take your (logical) point. Sadly, very few valves not designed for audio are any good for audio. The ECC82 is very definitely an astringent citrus fruit. |
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| dhaen |
EC8010,
| quote: | | Sadly, very few valves not designed for audio are any good for audio |
That too might be true. The funny thing to me is the number of valves that I knew in my previous RF life (teens) that have become "standards".
ECC88
EC88
ECC189
EF80
EF184
PCF80
Just a few examples...
Cheers, |
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| EC8010 |
| quote: | Originally posted by dhaen
The funny thing to me is the number of valves that I knew in my previous RF life (teens) that have become "standards".
ECC88
EC88
ECC189
EF80
EF184
PCF80
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I take your point. There are a few other applications that also require low distortion. RF front ends, FDM telephone amplifiers, and good IF strips. I'm not quite sure what the variable-mu ECC189 is doing in your list, but the EF184 is one of my favourites. It's a good triode, and it makes a good constant current sink. |
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| Sch3mat1c |
| quote: | Originally posted by EC8010
What is this nonsense? The Mullard ECC82 is a field scan valve (an application that does not require low distortion. The one remarkable feature about this valve is its consistency between manufacturers and samples. Selection is not necessary. They are all equally poor for audio. |
FU! I love 12AU7 ;) :cool: |
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| Ciscokid |
Hi,
Cool looking preamp. Where did you get the PCB for the rectifier?
ck |
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| Wardsweb |
| quote: | Originally posted by Ciscokid
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. |
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| dhaen |
| quote: | Originally posted by EC8010
I'm not quite sure what the variable-mu ECC189 is doing in your list, |
Nor am I, but I've seen it (and others) in use.
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, |
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| moe29 |
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
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| Lisandro_P |
| Excellent look and wiring work! You should be really proud. |
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| fdegrove |
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...:devilr:
Cheers, |
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| Wardsweb |
| You mean like these. ;) |
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| Wardsweb |
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 ****, 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. |
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| fdegrove |
Hi,
| quote: | | You mean like these. |
Yes,Sir..that's the ones.
| quote: | | 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,;) |
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| Sch3mat1c |
Yes, clear-top 12AU7s..(exactly as pictured) I picked 'em over top getter because they look much more 1337 ;)
(And it's not PAIR, it's a HEPTET! For output of course...a whopping 6W into 6.6k :D )
Tim, Senior Thread Hijacker :p |
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| Sch3mat1c |
Whoops...double posted...
Tim |
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| Wardsweb |
What's the scoop on your avatar
Sch3mat1c |
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| Sch3mat1c |
WOT Headphones amp. (Choky knows WOT as With Output Transformer. :cool: )
6DJ8 in parallel, parafeeding (RC coupling) a 50:50k ohm input transformer in reverse (mmm, mu-metal core).
Current power source is a crappy deal I made years ago, does 6.3VAC + 100VDC 15mA. |
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| Sch3mat1c |
Humm I attached a photo to that...oh well.
Full size of the avatar: |
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| Sch3mat1c |
Thanks!
Underside: |
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| Sch3mat1c |
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 |
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| 7N7 |
| quote: | Originally posted by dhaen
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 |
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| 7N7 |
| quote: | Originally posted by Wardsweb
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 ****, 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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