Headphone Choice for Paramounts?

[casanis]

I have a chance to pick up either a pair of Grado RS1i's or Senn HD650...used and at a very good price.

I'm quite happy with my current setup and am not looking to add an additional amp for headphone duty.

What's the general consensus for headphone impedance when driven with Paramounts (2A3 configuration) and Foreplay III?

Thoughts and or opinions most welcomed!

Cheers.

[johnsonad]

Look for something that enjoys a 16 Ohm impedance as that's what you're going to get with the Paramounts. The Senns are out. Why not find a pair is AKG K1000's?

[Paul Birkeland]

Sennhieser will work well, Grados will probably be too sensitive.

I'd add some series resistance for the Sennhiesers.

[johnsonad]

Sennhieser will work well, Grados will probably be too sensitive.

I'd add some series resistance for the Sennhiesers.

Why will they work well and would they work well without the series resistance?

[mcandmar]

The Grados are a very sensitive headphone so you will need an amp with a nice quite noise floor and low output impedance to drive them properly.  The Sennheisers are a lot more forgiving and seem to work well with just about any amp.

As to which to go for, that's a choice only you can make. I adore my Ms-Pros (RS1 variant), and never liked my HD650's, but many people would be the complete opposite so you really need to listen to both and decide for yourself, both are a very nice pair of headphones.

[casanis]

RE: the sensitivity of the Grados, I have been reading that a series added 120ohm resistor is standard on other amps. Would this addition help the sensitivity issue of the Grados matching up with the Paramounts?

[Paul Joppa]

The added 120 ohm resistor would help the Grado sensitivity issue greatly. Unfortunately the Grados in general do not like that resistor, it muddies the bass (I am told). I'm ot a headphone user myself, so maybe someonewith direct experience will add a comment?

[casanis]

Went for the HD650's... picking them up later today. Thanks for the info all.

[Grainger49]

Report back how you like the combination.

[casanis]

Picked up the HD650's this morning and hooked them up just to verify functionality.

They sound quite good, however, appear to be a little too sensitive. Thankfully I did not go for the Grado's!

Can anyone offer input on 120ohm resistors for the headphone output (type, brand etc...).

I have some 150ohms on hand, however, will be putting in a partsconnection order this week...

The Paramounts hum balance pots made a huge difference in quelling hum...

Will update accordingly.

[Paul Birkeland]

Toss the 150 Ohm resistors that you have now in and see how you like them.  (Clip leads to test if you like)

Also, wire your Paramounts for the lowest possible output transformer impedance.

How is the noise level without resistors? 

[casanis]

"Also, wire your Paramounts for the lowest possible output transformer impedance."

How will this affect the speaker outputs (currently wired for 8 ohms)?

I was hoping to add a switch to the speaker terminal o/p on each Paramount to go between headphone out (via internally mounted barrier strip) and speaker output.

[Paul Birkeland]

If you use the 4 Ohm configuration on your 8 Ohm speakers, you will sacrifice some output power but at the same time obtain better damping and a lower noise floor. 

If you want to be a true bad ass, you can convert your Paramount speaker outputs to balanced outputs (lift the ground from the negative speaker post, then put a 100 Ohm resistor from + to ground and - to ground), then add a 1/4" switching TR jack to each amp.  Cable up your headphones for balanced operation with two 1/4" mono plugs, then when you plug them in the speakers will cut out

[casanis]

Okay - thanks for the info!

Lots to chew on here...

The noise level from the Paramount is almost non-existent with the hum pots tweaked accordingly. (input shorted)

I am hearing some noise from upstream of the Foreplay when the TD-124 is selected through my Yaqin RIAA...the weakest link I'd say.

This sure is a slippery slope! Headphones are a great way to really hear what your system is sounding like...

[Paul Joppa]

The resistor - 120 ohms, 150 ohms, or whatever - won't make a lot of difference with the 300 ohm 650s. The resistor is mostly effective for low-impedance phones (like 40 ohm Grados). If you need to attenuate the headphone signal, it's better to make up an L-pad - two resistors per channel. That way you can retain a lower output impedance too.