Help with connecting cans to integrated

[2channel*]

I got a new integrated amp. I love it, except for 2 things:
1) Only one set of speaker outputs. I am used to using the B speaker outs to drive my Stax SRD-4. I wouldn't connect my A speakers to the back of the SRD. I have to switch back and forth by connecting/disconnecting. Major PITA!

2) No headphone jack!!! Who the "F" does that? I'm trying to figure out what I need to put between the per-out RCAs and the 3.5 mm jack of a pair of NAD HP-50s. Would a Schiit Vali work? Is it necessary? The Max out of the pre is given as 10 Vrms; while the max in of the Nads is given as 32 mW. If I try a simple breakout cable will I fry my nads? (Sorry. I couldn't help myself ;^)

 

[JoeESP9]

What's wrong with connecting your speakers to the back of the SRD-4? Bear in mind that I owned and used an SRD-4 and SR-34's (late 70's to late 80's) in conjunction with Magneplanars first and Acoustat ESl's later. If the switch on the SRD-4 had any negative audible qualities I'm fairly certain the rest of my gear would have revealed it. Incidentally, a headphone jack can't drive an SRD-4 in the first place.

 

[2channel*]

Thanks, Joe.
It seems counter productive to go to great lengths to assure the most direct, purest connection between speakers and amp and then stick a box with spring clips in the middle, plus I have another set of speakers connected to the SRD-4.
The headphone jack would let me at least use the NAD phones. Maybe latter invest in some planar magnetics. The Stax are getting long in the tooth and the channels may not be even, though I am having my hearing checked next week.

 

[whoaru99]

If I try a simple breakout cable will I fry my nads? (Sorry. I couldn't help myself ;^)

The NADs are low impedance cans. Almost certainly will present too much load for the pre outs to drive directly with using just an adapter cable.

 

[2channel*]

The NADs are low impedance cans. Almost certainly will present too much load for the pre outs to drive directly with using just an adapter cable.

Something like the Schiit would work?

 

[Djcoolray]

I'd return it...

 

[whoaru99]

Something like the Schiit would work?

Don't know, not familiar with that.

However, if it is a headphone amp suitable for low impedance cans then it should work.

 

[KingBubba]

A simple Niles switcher should do the job and stabilize your impedance to boot.

 

[JoeESP9]

I second the idea of using an external switcher. Unfortunately all of the ones I looked at use those awful spring clip connectors.

 

[2channel*]

I second the idea of using an external switcher. Unfortunately all of the ones I looked at use those awful spring clip connectors.

Same here, and I'm using 12 G speaker wire and would like to bi-wire. I posted a Wanted ad on another forum for the old Stax SRD-X pro that should solve the problem; but they would be rare today.

 

[whoaru99]

Does the Stax arrangement present a speaker-like load to the amplifier?

 

[JoeESP9]

Does the Stax arrangement present a speaker-like load to the amplifier?

IIRC the SRD-4 energizer presents close to an 8 Ohm load. It's designed to be connected to speaker level outputs. It's rated for 5 Watts continuous and 30 Watt peaks.

Other Stax phones are pure electrostatic not Electret like the SR-34/40. Their interfaces are line level driven and are dedicated power amplifiers.

 

[whoaru99]

Ok, so straight parallel probably isn't the ticket.

One can fairly easily build their own A/B switcher using any sort of speaker connections they so choose.

 

[2channel*]

IIRC the SRD-4 energizer presents close to an 8 Ohm load. It's designed to be connected to speaker level outputs. It's rated for 5 Watts continuous and 30 Watt peaks.

Other Stax phones are pure electrostatic not Electret like the SR-34/40. Their interfaces are line level driven and are dedicated power amplifiers.

Joe, I don't think the issue is electrostatic vs electret; I think it's purely related to bias. There are normal bias (230V) electrostatics, too. As I research more I find that Stax made several pre-amp/amp units that are compatible with the SR-40 and SR-30. Unfortunately, the few that are available are buy at your own risk, non-returnable, and cost as much as a new pair of Oppo PM-3s, so I'm ruling them out for now.

http://kenrockwell.com/audio/stax/sra-12s.htm

I suppose I could get any small amplifier and connect it to the pre-out of the Primare I32. Something like the Dayton DTA3116HP; but not as cheesey. What I like about it is that it also has a headphone amp. Does anyone know of a better product under $100ish?

 

[JoeESP9]

Joe, I don't think the issue is electrostatic vs electret; I think it's purely related to bias. There are normal bias (230V) electrostatics, too. As I research more I find that Stax made several pre-amp/amp units that are compatible with the SR-40 and SR-30. Unfortunately, the few that are available are buy at your own risk, non-returnable, and cost as much as a new pair of Oppo PM-3s, so I'm ruling them out for now.

http://kenrockwell.com/audio/stax/sra-12s.htm

I suppose I could get any small amplifier and connect it to the pre-out of the Primare I32. Something like the Dayton DTA3116HP; but not as cheesey. What I like about it is that it also has a headphone amp. Does anyone know of a better product under $100ish?

The SRD-4 Energizer has absolutely no active circuitry. None is needed for the SR-30/40 series phones as they are Electret based designs. Electrets are self biased diaphragms. Any "speakers" that are self biased (Electret) have a "permanent" charge on the diaphragm. This means they do not need a polarizing voltage. However, in my experience, after 35+ years the inherent charge in electret diaphragms has a tendency to dissipate. This doesn't apply to true ESL's (all other Stax models). They require an external polarizing (bias) voltage (supplied by the required/dedicated amplifier/interface) to energize them as do the electrostatic speakers I have and use.

 

[2channel*]

The SRD-4 Energizer has absolutely no active circuitry. None is needed for the SR-30/40 series phones as they are Electret based designs. Electrets are self biased diaphragms. Any "speakers" that are self biased (Electret) have a "permanent" charge on the diaphragm. This means they do not need a polarizing voltage. However, in my experience, after 35+ years the inherent charge in electret diaphragms has a tendency to dissipate. This doesn't apply to true ESL's (all other Stax models). They require an external polarizing (bias) voltage (supplied by the required/dedicated amplifier/interface) to energize them as do the electrostatic speakers I have and use.

Thanks, Joe. I didn't know the electrets were permanently charged. If they lose their charge after 35 years, can anything be done? My SR40's still sound great; but I have a pair of SR30s that have a serious channel imbalance. BTW, Do you know if the electrets can be connected safely to all normal bias drivers?

As for the solution to my I32, I have will get a cheap class D amp that has a headphone output jack and speaker binding posts and accepts RCA input from the I32's pre-out. That should kill 2 birds with one amp. I'll let you know how it works out.

 

[JoeESP9]

I don't know if you can connect a pair of SR 30/40's to the standard output on a Stax Energizer/amplifier. That's something I never tried. I gave the SRD-4/SR40's to a buddy years ago. He was living in an apartment building with neighbors that didn't tolerate any sound whatsoever from his apartment.

I have an SMSL SA-50. It would probably be more than adequate for driving a pair of SR-30/40's

 

[2channel*]

I was torn between SMSL and Topping. I found a TP30 Mk2 for a good price and jumped on it. I hope I made a good choice. I don't need the DAC and wish all the expense was invested in the amp; but who knows. I might get into desktop.

 

[2channel*]

The TP30 Mk2 arrived a few days ago. It a cute lil feller. It sounds pretty good with the stax and the NADs. I don't hear any distortion. I am leaving the volume almost at full and adjusting via the preamp.

 

[2channel*]

In case anyone is interested; I switched the output to the TP30 from Pre Out to tape out. Now I can mute the speakers when I listen to headphones, instead of unplugging the speakers. No Balance control though..
Also, I acquired a pair of Stax SRX-MK 3 (normal bias) and an SRD-7. The SR-40 electrets work with the SRD-7, too. There's no bias pin on them so they don't get charged.