Tube DIY Asylum

Do It Yourself (DIY) paradise for tube and SET project builders.

Return to Tube DIY Asylum


Message Sort: Post Order or Asylum Reverse Threaded

Citation V

70.184.212.128

Posted on July 27, 2014 at 13:38:17
Lee of Omaha
Dealer

Posts: 1800
Location: Omaha NE
Joined: September 8, 2006
We just serviced a customer's Citation V. We replaced a couple of tubes and rebuilt/beefed-up the power supply. We then hooked it to a pair of Snell C IIs for burn-in and a listen check.

On the 8-ohm taps the bass is phenomenal--deep, rich, rther amazing for a tubed amp. But the highs and to a lesser extent the mids are compressed and strident.

On the 4-ohm taps the bass suffers a little as I've generally come to expect from the Snells, but the mids and highs open up. They're natural, not strident, really nice.

The other amp that has had the "8-ohm sound" is the power amp section of a rebuilt Pioneer SX-1250.

That leads me to wonder if there is an impedance mismatch or other oddity in the Snells. The woofers seem happier with a higher impedance amp, the mids and highs with a lower impedance amp? Why on earth would the woofers sound better hooked to a higher impedance? I can understand the mids/highs wanting a low-impedance amp/tap (damping, control).

 

Hide full thread outline!
    ...
"oddity in the Snells", posted on July 27, 2014 at 16:33:00
Chip647
Audiophile

Posts: 2631
Location: The South
Joined: December 24, 2012
Have you ever looked a Snell 100,000 part count crossover? Yes, they are odd, very odd.

 

Sounds like the woofer is an 8 ohm load, posted on July 28, 2014 at 09:28:37
Ralph
Manufacturer

Posts: 4769
Location: Minnesota
Joined: April 24, 2002
And I would not be surprised to find out that there is a substantial impedance peak in its curve.

The mids and highs sound like they are more in the 4-ohm range. Im not a fan of negative feedback but in this case it seems like the amp might need a bit more.

Plan B: Biwire the speaker, run the mids and highs off of the 4 ohm tap, ran the woofer section off the 8 ohm tap.

Plan C; Get a set of ZEROs to run the mids and highs, and run the woofer direct.

 

RE: Sounds like the woofer is an 8 ohm load, posted on July 28, 2014 at 10:38:15
mcgjohn@yahoo.com
Industry Professional

Posts: 501
Location: Midwest
Joined: February 5, 2008
would tend to agree with Ralph. Over the years I have owned most of their product line and model variants. Have never found the Snells to be a good match with tubes, unless you're talking 200 watt tube amps. the snells did the best with 250 watts+ of solid state, high current power. and if the amp had a stiff enough supply to double the current as the impedence was halved, even better. I tried to power a pair of C5s, and AIIIi's with a 75 watt tube amp. Sounded pretty much as you described. The only exception to this may be the small K2's which were better than their bigger brothers with tubes, but still sounded better with high current SS power.

best.

 

Page processed in 0.024 seconds.