SRG II Part 1

Solo SRG II Part 1

Here is the first part of my SRG II review.  It follows the PSU1 review here:

http://www.gspaudio-community.activeboards.net/forum_posts.asp?TID=712

Part 2, which covers the SRG II sound performance is here:

http://www.gspaudio-community.activeboards.net/forum_posts.asp?TID=717


The SRG II is housed in a two-piece, anodised, extruded-aluminium case measuring approximately 117mm high x 46mm wide x 163mm deep.  The quality of the case extrusion is very high.  Front and end plates, with silk screened legend, are held in place with flush-fitting socket cap screws.  Fit and finish of all plugs and sockets is to a very high standard indeed, and an grounding post is provided to reduce noise when using the energy efficient switch-mode Green power supply.  I'd give the casing 9 marks out of 10, docking a half-mark for some small finishing imperfections on the edge of the end plates and the other half-mark purely for me - I'd rather see thicker end plates with engraved rather than silk screen printed legends, even if the print quality is high.  I can be fussy…  I do like the turned and brushed finished control knob - just the right size mechanically and aesthetically.

The SRG II comes with two A4 sides of instructions, detailing how to get the best out of it.  Almost touching on irony is that eco-friendly, double-sided printing was not used.  Tongue a little in cheek here!  The instructions are clear, comprehensive and easy to understand.

I opened up the powered-up unit for a look-see.  Power supply-wise, the warmed up PSU1 settled right down and hooked up the scope was showing a steady a steady 24.0625V average with an occasional peak-to-peak ripple of 312.5 mV into the SRG II.  All components used were of good quality and the solder work was superb.  Quality of the workmanship was very good indeed.  The pre-regulated DC (from the PSU1) is further regulated by another fixed regulator, and feeds a single op amp whose identifying marks, for IP reasons, have been obscured.  Component placement appears to be well thought out, and it was good to see the implementation of a true star-ground.  The PCB is vanilla FR4 styleee without silk overlay, solder mask and all that whathaveyou.  Of course, these are unnecessary in this application, and the board allows effortless in-life changes to be made to the design without having to scrap a board run.  A good idea, seeing as GSP appear to run a continuous development policy.

BTW, I do like the understated green LED on the front panel, rather than the burn-your-retinas-out blue that is so commonly fitted nowadays!!

Following on from my comments about a locking DC power jack, this is an amp designed to be left on continuously in a professional, studio environment.  As the SRG II really needs a couple of days to come on song after being powered down, a locking dc jack would prevent the power cable from being accidentally pulled out and the unit de-powered.  A bugger when you're just about to mix-down your master...

I had the notion that a super-regulated power supply, replacing the PSU1, might have some benefit, and I spent some time converting a 5V ALWSR I had pre-built.  However, a fault, which I did not have time to address, meant I was unable to use it.  Moreover, the SR would only be feeding the fixed reg, and this would not have been much benefit.  A trick PSU feeding the op amp pins directly would be a better bet, and I think the option to do this could be retrofitted to the SRG.  While I'm on the subject of "hot-modding" how about the option of pass-through like the Novo has (simple reconfig), upgraded attenuator, or even a "blue-print" version with higher-tolerance hand-matching.  All priced options.  Mad?  Car manufacturers offer options, and I'm not just talking about the "Special Editions" with different paint and wheel trims.

Having messed about with the mechanical side of the SRG II, it was time to let is cook for a couple of days before having a first listen…

Stay tuned.

Jon

PS Edited for spolling, grammar and a load of syntax that a decent proof would have caught!!


Edited by jonclancy - 05 Dec 2009 at 4:39pm