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-   -   Bottlehead Seduction Phono stage (http://www.diyaudio.com/forums/tubes-valves/13561-bottlehead-seduction-phono-stage.html)

Magnetmaz 9th April 2003 02:49 PM

Bottlehead Seduction Phono stage
 
My turntable will be arriving shortly, and i need to build a phono stage. ( preferably tube )

I really enjoyed building the Bottlehead foreplay, and was satisfied with the results...so i was wondering if anyone had any listening experience with the Bottlehead Seduction?

Does anyone have the schematic on-hand?

-Maz

Magnetmaz 9th April 2003 05:12 PM

Well, then let me ask this question :


I'm considering building either the Seduction, pictured here :
http://www.bottlehead.com/et/adobesp.../seduction.htm

which costs $250 for the complete kit and uses 1 6DJ8 per channel ( tubes included in price ). It's PTP wiring, of course.


vs.

The Hagerman Cornet, pictured here :
http://www.hagtech.com/cornet.html

which i estimate to cost me $205.00 and will require slightly more building ( cutting the chassis, etc ) and which uses 2 12AX7 (ECC83), 1 x 12AU7 (ECC82) , and 1 x 5Y3GT. All on a PCB.

(tubes not included, but i have all of them)

Which would you do?

-Maz

SY 9th April 2003 05:53 PM

The Cornet would be my choice, since they actually had a schematic on their web site. Not a particularly impressive design, but it could help you get your feet wet.

pedroskova 9th April 2003 07:49 PM

Go with the Seduction:
PTP, filament snubbers,clever and compact grounding layout, CCS loading coming soon(at extra cost), and cosmetically, it will match your foreplay.

...plus the usual support should you go astray.

Le Basseur 9th April 2003 08:03 PM

Forget the Hagerman,as you should forget every RIAA preamp using those unhappy ECC 83 and equivalents!
Does anyone out there remembers the fact that ECC 83 rolls off sharply at 31 KHz?!? ....meaning that when the whole beauty and charm begins (I'm talking of upper harmonics and transients contained by LP's),here it comes this...this LO-Fi tube and ruins all?!?
With a ECC 88 you're happy all the way ,but you'll have to give it the proper "food" (fancy HT supply!) and,maybe,trying some different types,till you reach Nirvana....:goodbad:

Magnetmaz 9th April 2003 09:03 PM

I appreciate both of your input.

Your points are well made, pedroskova. Costmetically though, it doesnt matter to me. I will build a uniform chassis type in the future, but for now i want the goods. Don't care much about support, as you guys are my free tech support :)

I'm not sure what to think about CCS loading. I have heard statements that sound like "gives it a more modern sound, vs a vintage sound" ...and i'm not sure that's what i want.

Why isnt every tube amp CCS loaded?

At any rate, i'm leaning towards the cornet, and i'm not sure why. Partly because it takes bottlehead 6 weeks to ship something out. Partly because i have some NOS tubes it uses that i want to put to use. Partly because i've never done a PCB layout..soldering...etc.
Partly because i want to actually construct a chassis myself, with punching, drilling, mounting. Also, its $50 cheaper according to my calculator and i can order the parts as i have the cash...as opposed to the $250 upfront from bottlehead.

Seduction would be way easier, though.


I would like to hear why the Cornet isn't particularly interesting, though...and also my question above about CCS loading.


-Maz

SY 9th April 2003 09:30 PM

I said "impressive," not "interesting." Anyway, I'm unimpressed for a few reasons:

1. 12AX7s. Not a great tube in the first hole for reasons of noise and bandwidth.

2. 12AU7 CF. There are much better tubes for that application. Transconductance is everything.

3. Passive EQ. Hey, I use passive in my own preamps, but the particular way this is implemented here will assure you that the EQ will drift out of spec as the tubes age. And will need retrimming each time the tubes are replaced if you want to maintain EQ accuracy.

But these are pretty minor quibbles. And the way this is set up, a CCS will definitely cause the EQ to be off-spec. If you retrim, the sensitivity of EQ to tube parameters will be even worse. And CCS will reduce the bandwidth.

JBasham 9th April 2003 09:32 PM

I love the Bottlehead C4S loading circuit!

I've put it in four tube amps now. Every time, it's made a great improvement:

1. Power supply ripple rejection -- quiets down the background hiss/hum

2. Better bass slam & impact

3. More resolution & detail

I don't have the Seduction, though.

Magnetmaz 9th April 2003 09:34 PM

Despite what you mentioned above you would still go with the Cornet?

Could you suggest a better 3rd alternative along the same lines as these two projects?


-Maz

pedroskova 9th April 2003 09:47 PM

Voltsecond ccs'ed the seduction(his own design) and remarked that the change was huge and all for the better. Mr. Joppa designed the RIAA network to accept the ccs with no changes(the riaa curve is barely effected). IMO - if you want to build a chassis, build one that accepts both the foreplay and the seduction circuits, with a second chassis that houses the two separate PSU's. Best of both worlds.;)


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