New Posts New Posts RSS Feed - Achieving High Fidelity Sound
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Welcome to the Graham Slee Audio Products Owners Club


Open to all owners plus those contemplating the purchase of a Graham Slee audio product wishing to use our loaner program: join here
Subscribe to our newsletter here (Rules on posting can be found here)

Achieving High Fidelity Sound

 Post Reply Post Reply Page  <1 345
Ash View Drop Down
Senior Member
Senior Member

Joined: 18 Mar 2013
Location: Dorset
Status: Offline
Points: 2937
Post Options Post Options   Thanks (0) Thanks(0)   Quote Ash Quote  Post ReplyReply Direct Link To This Post Posted: 25 Dec 2019 at 10:59pm
So I haven't updated my section here for quite some time but I still have been motivated to pursue high fidelity sound reproduction.

I have recently been faced with a little dilemma; I have the MySphere 3.1, which is a superb sounding headphone, but did not possess any Graham Slee electronics to connect it directly to, as I had sold my Bitzie and Solo ULDE quite a while back and only have the Proprius from the Majestic now.

The MySphere 3.1 have low impedance (15 Ohms) and high sensitivity (around 96dB/mW, same as HD800) so hardly anywhere near an ideal load for the Proprius. The dial position on the monoblocks would have to be so far anti-clockwise to avoid overdriving and hissy noise floor, then there is impedance matching. I bought a resistive cable when I purchased the headphone, which increases the impedance of the 3.1 from 15 Ohms up to 110 Ohms (close to that of the AKG K1000, which is 120 Ohms) for a slight drop in sensitivity. Although the sensitivity would still be close to that of the Sennheiser HD800. Still not an ideal load. So, I got wondering how I could make them a suitable load for the Proprius, seeing as if I couldn't, I would have to pay to re-buy a Solo ULDE in order to drive them from the Majestic.

I got talking with Heinz Renner again, the creator of the headphone. I described my intentions of using the Proprius with the MySphere 3.1 because his past creation, the old AKG K1000, was such a great pairing for the Proprius and I wanted to imitate that compatibility because both the Solo UL and Proprius were equally capable at driving the K1000; I could not tell the reproductions apart from one another. So Heinz kindly went away and did some calculations based on the specs of the equipment then soon after personally made a voltage divider cable for me with banana plugs that plug straight into the Proprius terminals and posted it off to me for testing.

Well I received it a few days ago and still need to test it, which I will do over the next few days. This cable allows me to use the MySphere 3.1 symmetrical/balanced with the Proprius and should grant the MySphere the same impedance and sensitivity characteristics as the AKG K1000. So I should be able to connect them both simultaneously as well and directly compare the reproductions, which will be very useful for analysis.

Now I have abandoned the sale of my Proprius and will not require the Solo ULDE after all. Excellent, as it saves me money and still grants me the option of connecting speaker drivers if I need that facility. Over the next few days, I will be able to verify all this. I may try connecting the Majestic OTG USB to my LG V30 and check if that works too. Shall update soon.

Edited by Ash - 25 Dec 2019 at 11:12pm
Back to Top
Aussie Mick View Drop Down
Senior Member
Senior Member

Joined: 21 Feb 2014
Location: Bendigo Aust.
Status: Offline
Points: 716
Post Options Post Options   Thanks (0) Thanks(0)   Quote Aussie Mick Quote  Post ReplyReply Direct Link To This Post Posted: 25 Dec 2019 at 11:33pm
That’s an interesting development, Ash. I look forward to hearing the results.
Rega RP8/Ortofon 2M Black/Rega Apheta 2 - Reflex M/Elevator EXP - C.E.C. TL5 CD Transport - MacBook Pro/Roon - Majestic DAC - Solo ULDE (Focal Elear) - Proprius - PMC Twenty5.22
Back to Top
 Post Reply Post Reply Page  <1 345
  Share Topic   

Forum Jump Forum Permissions View Drop Down

Forum Software by Web Wiz Forums® version 12.01
Copyright ©2001-2018 Web Wiz Ltd.

This page was generated in 0.078 seconds.