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xcortes · 3353

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Offline xcortes

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on: January 12, 2015, 07:07:36 AM
Been trying a Paramour with my Quads. The mids and highs are heavenly. And the bass is good but boomy. From a post by PJ that boominess is to be expected:

 "The problem with no-feedback triode amps is that they do not have a high damping factor. For the ESL-57, that has two effects - the bass will be boosted in the region of the resonance which appears to be around 80-100Hz, and the treble will be depressed at high frequencies. This applies to both push-pull and single ended".

The same post provides the solution:

"A practical solution would be a modest amount of feedback, let's say less than 6dB. Not of course widely available outside of custom designs."

And Seductor comes to the rescue: "with SEDCTR technology, we can make them sound a lot like SET amps. We can also obtain a lower output impedance and higher damping factor than is possible with no-feedback SET designs. This means the amps can successfully drive a wider variety of speakers, since almost all speakers are designed for high-damping amplifiers."

Two questions:

1. Are there Magnequest products that could be used as upgrades in Seductor plate chokes and output transformers (I'm assuming it's parafeed)?

2. Are there any sonic penalties from strapping to 8 watts?

Thanks

ps. I have a set of refurbished quads on order so I'm serious :)

Xavier Cortes


Offline Paul Birkeland

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Reply #1 on: January 12, 2015, 08:09:51 AM
The Magnequest upgrade for the Stereomour ought to work as an upgrade.  If you plan to bridge the Seductor, the flexibility of the stock output transformers will be very helpful, so you may want to just upgrade the plate chokes at first.

The sonic penalty for putting pentode output stages in series is minimal.

-PB

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline xcortes

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Reply #2 on: January 12, 2015, 08:20:27 AM
Thanks Paul,

Could I strap more than two in series? Maybe four? What about eight?

Xavier Cortes


Offline Paul Birkeland

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Reply #3 on: January 12, 2015, 08:34:45 AM
The number of amps that you can use will depend a bit on the actual secondary impedance that you like the most with the Quads.  I would suggest listening to the ESL's with a single Seductor on the 2, 4, 8, and 16 Ohm taps to get a feel for the bass and treble differences between taps.  If you like the sound on the 8 or 16 Ohm taps, then you can string a ton of Seductors together (bridging two stereo amps together isn't covered in the manual, but is possible).  If you need the 4 Ohm tap, then you'd be down to just one stereo amp per speaker.

If possible, you should also keep a Fix handy, as the treble correction section intended for single driver loudspeakers may fix the response issues that could pop up from the impedance dip in the treble. 


Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline xcortes

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Reply #4 on: January 12, 2015, 08:41:00 AM
Cool.

Thanks

Xavier Cortes