Superior Performance Hi-Fi Products

All Headphone Amps >> Solo Factory Upgrade

Graham Slee Solo Headphone Amplifier since Spring 2004

Solo Factory Upgrade

Got a Solo headphone amp like this one?

Great news! The new Solo Ultra-Linear Diamond Edition board fits! We can upgrade any Solo produced since mid 2004 to flagship status! DIY enthusiast? No problem! You can buy the board and fit it yourself - read more

We've made many great improvements to the Solo sound over the years, none more so than Graham Slee's innovative development of our Ultra-Linear voltage amp technology - all the good sounding things valves do without actually using them! Then late 2011 the breakthrough came - he got the background noise (hiss) right down to -95dB (that's around -105dB "A" weighted) making it much better for In Ear Monitor users. The Diamond Edition version is nicely rounded off by it's improved output current delivery, meaning it will make even the most difficult to drive headphones sound better.

We always look after our customers and what better way to add to our service than making the latest developments available to you for a lot less than having to buy a brand new Solo Ultra-Linear Diamond Edition?

Don't forget you won't appreciate the full performance of the Solo Ultra-Linear Diamond Edition headphone amplifier without our PSU1 power supply, so if you haven't already upgraded to the PSU1, now's the time!

Solo Ultra Linear Upgrade PCB Assembly

What's Involved?

The Solo Ultra-Linear Diamond Edition headphone amplifier factory upgrade involves fitting a completely new fully tested PCB assembly. It's like getting a brand new headphone amp but reusing your existing case.

Normally your old board will be sent for recycling in line with the waste electrical and electronic equipment directive (WEEE), but if you want your old board back you need to tell us in writing when you send us your old Solo.

The upgrade service cannot offer you the latest front panel because...

  1. It won't fit all case styles (it would be unfair for some to have and others not)
  2. It wouldn't be reuse! (against the spirit of the offer)

New Board Specs

(The same as a brand new Solo Ultra-Linear Diamond Edition headphone amplifier)

Headphone impedance range: 8 to 2,000 Ohms / 16 to 600 Ohms preferred

Power output: (rms, both channels fully driven at 1% THD)
32 Ohms: 140mW/channel; 600 Ohms: 30mW/channel

Input sensitivity (for specified power output into 32 Ohms): 511mV rms

Input impedance: 37k Ohms at max volume; 50k Ohms at min volume

Distortion: (THD plus noise at 9 o'clock volume control setting (qtr power))
10Hz-20kHz: better than 0.04%; 10Hz-1kHz: better than 0.02%

Frequency response (±0,-3dB) 10Hz - 35kHz

Output noise: (22Hz-22kHz, quasi-peak/un-weighted) -95dB

Channel balance: better than 1dB

Crosstalk: Left to Right -56dB; Input to Input -68dB

Input selector centre-off position: non-shorting; -38dB at max volume with 2V rms input (ref: 1kHz and 10kHz)

Output Stage: Bipolar class AB

Supply voltage: 24V DC unipolar

User Reviews

From members of the Owners Club

"...Then there is the low end bass. Marillion uses synthesizers to add low end bass and give some songs tremendous scale (like movie soundtracks). The Ultra-Linear delivers it in spades and with detailing. Without clouding the rest of the sound-scape..."

Francisco [on the non-Diamond Edition Ultra-Linear]

"Diamond Solo UL has been left on for over 4 weeks now and I guess the initial stage of burn-in is more or less complete? There are some notable improvements over Solo UL MK1:

1] Much less hiss (I can hardly hear any hiss during low passages in tracks); 2] It certainly has improved on soundstage when paired with the Grado PS500/SR325is (32 ohms). I feel like I can now identify where instruments are located or positioned - and that's fun! In the past, I felt everything was thrown at me in 2D compared to now which has added depth and better separation of instruments... I do feel that the Diamond UL Solo now drives Grados much better than before. It is a worthwhile upgrade! Thank you Graham!

J633295

How to Order

First thing to do is use our VIP ordering system to place your order (read more here), then carefully parcel up your Solo and send it to us - we do the rest.

If you're not in the UK or an EU country you should bear in mind that with some shippers we have to pay import duty to receive your parcel, and we'd have to add that to your bill. It's about 5% of the value you declare - we leave that up to your discretion when sending your old Solo to us.

For PRC and Russian Federation owners where there may be customs difficulties please contact your Graham Slee agent.

Price

Solo Ultra-Linear Diamond Edition headphone amplifier factory upgrade: £262.80 GBP (pounds sterling) including 20% United Kingdom VAT. Price does not include shipping.

PSU1 power supply (recommended): £169.96 GBP (pounds sterling) including 20% United Kingdom VAT. Price does not include shipping.