Winter Progress

The build continues at its own glacial pace with doors and ventilation getting a look in as the seemingly endless pile of parquet flooring blocks gets trimmed ready for laying.

Parquet Jenga tower

Myself and Roger have spent many an hour in gloves and masks working our way through the parquet and have got past the halfway point (~400 blocks). This is a picture of the blocks being dried after sponging off the sanding dust.

The air extraction fans have been plumbed into the exit box on the roof and I have dropped insulated ducting through the control room ceiling to test the custom silencer. It’s a simple chipboard box lined with acoustic plasterboard, which makes it a weighty bugger, to create a split with two direction changes to maximise absorption through reflecting the sound waves around as much as possible. The cross-sectional area also increases from inlet to exit (which is the opposite to the extracted air flow). The box was then lined with various acoustic foam materials I had lying around. As the box is split I could alternate linings to test which worked best. The final lining was then glued in place and quickly photographed with a variety of Sylvanian Family toy dioramas…because it seemed like a good idea…

The basic extraction silencer box

Extraction silencer with lining

Sylvanian Families hanging out in the silencer inlet

Completed silencer propped up for testing

Once the silencer was sealed up I managed to lift it onto some saw horses and plug in the ducting to check it performs as I planned. The result is a complete loss of the air rush and fan noise except for the lowest frequencies which are only audible if you put your ear to it. Considering the unit will be installed just below the ceiling that won’t be a temptation.

The control room doors have now been hung and are awaiting handles and sills. Though they are basic fire doors, they still weigh more than I’d like when fitting them. Now they’re on their ball bearing hinges they seem so light…bastards! They’ll still need to come off again before the final fit as seals need to go in yet.

Inner control room door hung

Outer control room door hung








And finally…the distribution amplifiers I mentioned in the last post have been tested and despite the ‘not-exactly-hifi’ spec of the initial buffer IC (UA727) they sound great and at minimum gain punt out a respectable balanced line level, but the gain trim pot allows for another heft which I couldn’t measure as I was just testing it through my Fireface line inputs, which on the Lo-Gain (i.e. above +4dBu reference) setting clipped before the distribution amp even sweated. I think driving up to 10 metres of cable to the monitor mixers in the live room shouldn’t be a problem then! They sound great, or at least transparent, so headphone mixes will be nice and crisp. Lovely.

Double glazing

Two panes of Optilam Phon hanging out in front of the harmonium

Today the glazing turned up – two 1m x 1.5m panes of Pilkington Optilam Phon, a name reminiscent of a Thai noodle dish. One is 10.8mm thick and the other is 8.8mm. They’re both made of two glass sheets bonded to an extra thick (0.8mm) laminate layer. I hope my calcs for matching the wall they will be sat in are about right; if not I shall be inserting a third panel between them in the frame (I am planning the frames to have a gap for such an event – nothing worse than having to take the whole lot out.

Optilam Phon – 10.8mm and 8.8mm



Whilst waiting for the glaziers to turn up this morning I continued the kind of obsessive task that makes building a studio suicidally long-winded for someone like me: drawing out the schematic for a distribution amp module. Years ago a friend and I bought two 3U racks of eight amps that drive 10 balanced outputs (600Ω) from one balanced input. I have decided to put one rack of them to use as the drivers for the eight channel headphone monitor mixers I shall be making for the live space – these suckers will be able to send to 10, which is 5 more than I think necessary for the space here. I can’t take any circuit for granted and have an Abbey Road approach to gear as I must know how it works and thus how to fix it. There aren’t any schematics available for these so I shall draw them out myself, which means lots of holding it up, flipping it over, prodding with hte multimeter and scrawling on a notepad. I’m most of the way there and will no doubt come up with a modification or two to make for a slightly better signal path (they’re a little lacking at the top and bottom, or a little midrange heavy depending on how you look at it). Here’s one now…

1×10 balanced distribution amp module

The large black box is a mains transformer as each module is self contained, thus no overall PSU problems, and having spare modules means I can swap them out mid-session if any futt-out. The input transformer is a cute little Beyerdynamic number. The UA727 dual op-amp that follows this is not a great delight on paper so I shall do some tests to see if (a) it sucks and (b) how to swap it out if it does.