[stlblue]

Greetings:

Any experience/thoughts using a Tripath amp (& SLA) w/ Altecs? I have some 604E's, which are 16 ohm. I have read mixed impressions of the amp mated w/ 16 ohm/coaxial speakers. I would use a tubed preamp w/ such a system, as i believe a passive volume control would not be sufficient w/ an Audio Note DAC. I have placed an order for a Sonic Impact to test, but am waiting like many others for oders to be filled.

Any insights are greatly appreciated.

stlblue

[Dmason]

I know there were some senior audiophools playing around with the SI with different Altec duplex and biflex on fullrange forum, which I think are 8 Ohms. 16 would not be a good thing, but the absolute quality of the 604 represents to me allowing the T amp to sound its best. (bias acknowledged.)

I know there is someone on these threads that has some autoformers coming soon, for trial. Simple reduction would make the Altecs and T amp a SUPERB, world-rocking combination. I know the sound of both, and I would head straight for the autoformer section of your grocer on that one

Can you get more Altecs???

[Panelhead]

Greetings:

Any experience/thoughts using a Tripath amp (& SLA) w/ Altecs? I have some 604E's, which are 16 ohm. I have read mixed impressions of the amp mated w/ 16 ohm/coaxial speakers. I would use a tubed preamp w/ such a system, as i believe a passive volume control would not be sufficient w/ an Audio Note DAC. I have placed an order for a Sonic Impact to test, but am waiting like many others for oders to be filled.

Any insights are greatly appreciated.

stlblue

  My use has all been with 15 ohm Lowthers. They do not have a crossover, so the impedance climbs with frequency. The SI has plenty of power in my system.
  The Lowthers are a little more efficient than the 604's, 100 dB, but you still should have as much power as a 2A3 SET.
  The availabe power from the SI is halved again with the high impedance, so 3 1/2 watts or so is it. But the current demands are halved also.
  You should have no problems driving the 604's. But depending on how you use the SI the tube preamp may have an issue. I bypassed the volume pot on one of mine. The input impedance of the 2024 chip is 10K. Most likely the preamp will not like seeing such a low load.
  If you open the stock pot up all the way, the preamp will see 9K. That is a 100K paralleled with 10K. Unless the preamp is real high current and has real big coupling caps the low end response will suffer.


                        George

[stlblue]

Thanks for your reply, Dmason. OK, let me ask you this, please: In lieu of a passive x-over, would an active unit help this issue? I have an ARC electronic-tubed x-over (collecting dust). Would two T amps connected straight to the drivers reduce the 16 ohm effect?

Regarding getting more Altec, not sure what you mean? I really don't want to replace these. I just got them back from Great Plains. They have new cones/diaphrams, are remagnetized, and have had the bug screens removed. Bill deems them "As new...never will need to replace them."

Many thanks for help,

stlblue

[Dmason]

More Altec 604's. For ME, that is. I love those things. It doesnt get any better. My all time favorite noisemaker. The old A7/604 VOT is what got me hooked, years ago. Powered by a Hammond organ triode amp no less.

The drivers both are rated at 16 Ohms, and the ARC tubed XO would be a nice thing to perhaps try anyway. the impedance rating is indicative of just how old the design is.

[Ulas]

Any insights are greatly appreciated.

You could add a 15-16 ohm, non-inductive resistor across the speaker terminals. The amp will see an eight ohm load, more or less, but your speakers will get half the juice. That shouldn't be a problem with sensitive speakers. Or you could download the Tripath data sheet and read about the circuit modifications they recommend to accommodate high impedance loads.