Turtlerock Forum

well the spit and polish is done

four pairs of racked MCI JH-500 channel strips for sale - $2,900 each

here's the details again :

univeral supply 100 to 240Vac
all transformer in and out ( jensen mic transformer, stancor line in and line out )
switchable phantom
High Z DI input on front panel
phase rev ( mic and line )
sweepable HP filter 30Hz to 300Hz
four band EQ - fully switched - no pots! Overlapping mid bands , treble peak or shelf.
Output level control - with a "cal" position for unity gain on line inputs

I'll provide warranty on these for at least a year and probably longer and have spare ICs etc


Monster headroom - this thing runs on 74V power rails, over double most solid state equipment- max 30dBu input and output levels

oh...and this could well be the only bit gear you'll ever own that labels the mic gain pot - MIKE !!

How do these sound?

Hey Rob,

They look great but just got my Quad Eight's, so a little out of the question.

I am however intrigued by the switchmode power supply. Personally I'd rather see a transformer and linear supply, but am obviously open to your more informed opinion.

So maybe tell us a bit about the switchmode and honestly whether it's a good thing or not. I've heard that when they go south, they really go south.

Chris

Hey Rob
Nice racking - I wish I had the $ to snap up a pair for that "Imagine" sound - these are really nice EQ's
I'll see if I can land a bigger paying job in the meanwhile.....
If there is still a pair around in a couple of months I may squeeze my freshly packed wallet...Nice work!
Chris Townend

fair question about the switchmode PSU, so here's my thoughts

there are three practical considerations
space ... it would have been very tight or impossible to fit a transformer and linear supply in the case.
universal voltage ... to make these available to run on 110 to 240V AC, a more expensive transformer would be required and the required transformer to yield the high voltages that the module need mean that it is hard to get the right transformer off the shelf anyway .... at any mains voltage
EMR - the MCI channels have 3 audio transformers and two inductors in them and proximity to a mains transformer will cause mains hum and buzz to be induced into the audio path. As it stands with the SMPSU modules there is NO hum or buzz in the noise floor. Analysis of the spectrum of the noise floor shows it to be pure white noise at ~ 80dBu.

The SMPSU also means that for those with wandering mains voltage you won't get regulator drop out ( buzzzzz ) if the mains voltage sags.

I've followed up the reliability of these SMPSUs and are there are several hundred out there in use and none have failed in the past couple years. Should they fail ... and anything can fail ( and most things will fail one day ) They can be replaced for around $50 and all you need is a pair of side cutters and screwdrivers and 15mins to replace. This is less than even the likely labour cost of fixing a failed linear PSU.

As to how they sound...I find it very hard to put words to sound but I definitely believe they are good, the EQ is very powerful, especially the overlapping mid bands and you can boost forever because of the huge headroom. And remember it is all switched, so settings are repeatable and recallable.

I go south often - really south

Switching power supplies have been in audio gear for a very long time.

They're in lots of audio things, especially synth equipment, since the mid 80s (and earlier, if you just look at voltage inverter circuits)

Generally you want a switching frequency way above audio frequency, so that if any noise does get in, it's not at a frequency that disturbs anything, which meant some special things had to be taken into consideration back in the 80s, making music industry's acceptance of SMPS a bit slower than the rest of the world because of the level of performance it required from power supplies made them very expensive - but modern SMPS modules using modern low gate capacitance (= fast switching) FETs all run really fast, because you get size vs power gains that way anyway.

And because the switching happens in a very small area, it's very simple to keep the loop size small in the switching section where all the noise happens, so you're generating way less level of stray magnetic field than you'll get from most big transformers, too. (though of course a very different kind of stray field, too....)

I just had to bump this back up to the top of the list

surely one of you basterds out there want one of these!

2 left...make an offer before I take them over to the dark side

2 packets of iced vovo's :D

Make an offer hey!!

haha!

I'll start with my usual offer of $80 and we can go from there.

thanks Mat, that helps

ok...i'm bumping this back up from the end of the list.

Trockers...make an offer above $2000, lets try and keep them in the clubhouse. You need this MCI magic and I need the bucks.

rob wrote:ok...i'm bumping this back up from the end of the list.

Trockers...make an offer above $2000, lets try and keep them in the clubhouse. You need this MCI magic and I need the bucks.

Done deal Rob. I'll take it. I'll email you to discuss.

cheers

Done...and all gone...gee that was easy!

So does that mean they are all gone ?
Cheers

indeed

ok folks, the MCI JH-500 is back

i've just racked up another pair and these are available for sale. $2,500

same as the ones in the photos, but the gain knob is bigger ( that has to be a good thing )

I have a pair of these from the Proharmonic workshop.
They have heaps of gain (too much actually) and good musical eq (beefy and versatile)

You can't go wrong getting a set of these from Rob.