What equipment have you built recently?

BobM · « **Reply #20 on:** 27 Feb 2009, 12:57 pm »

I really envy you guys hand building tube amps and tube preamps. I never got into that end of the DIY world, but someday I might. Nice stuff there fellas. I'm sure it sounds wonderful.

Bob

BillB · « **Reply #21 on:** 28 Feb 2009, 05:51 am »

Even if it's crap we convince ourselves otherwise.

TomS · « **Reply #22 on:** 2 Mar 2009, 04:09 am »

Oh, does "almost done" count?

This is my DIYAudio "Pumpkin/Shunty" dual mono balanced preamp with dual shunt regulated power supplies. The AC supply will be separately housed with the dual toroids shown and built in Felix conditioner. The aluminum plates are temporary heatsinks until the correct ones arrive. They do run HOT! With +/-36v rails, the modules can easily swing +/-20 volts balanced to drive my monoblock First Watt PassDIY F4 clones to full output in Class A (finally) for my Emerald Physics CS2 woofer section. They're set up for about 19db gain, easily matched to the 15db of my F5 for the CS2's compression driver/waveguide. All I need now is a decent case to put them in and I'm in business. They do play music, at least on the bench listening setup

mgalusha · « **Reply #23 on:** 2 Mar 2009, 04:16 am »

Your bench is too neat Tom, it disturbs me.

Since we have moved to almost done... I've been building a custom DCX mod for a friend, his won't have the Jan Didden analog board but I'm hoping it sounds at least as good but of course without the volume control. Reworking the output stage from 4 op-amps/channel to 1 and it will be direct coupled. The input stage has been interesting, using an LM4562 for an input buffer feeding a OPA1632 diff amp. I had some TI TL431 shunt regulators on hand so I am using one of those to provide the 2.5V for the ADC biasing. I've altered the gain architecture to hopefully maximize the ADC/DAC levels to provide the best SNR and maximum bits of digital conversion.

Glen B · « **Reply #24 on:** 2 Mar 2009, 09:53 am »

I built tube amps and speakers in the '70s and early '80s. Now I do mostly restorations and mods of vintage equipment, and other projects. Following are links to galleries on three of my projects.

DIY balanced AC power conditioner with surge protection:

http://img.villagephotos.com/p/2003-5/191557/1741050

Refurbished SAE 2400, upgraded input and output connectors; replaced captive power cord with IEC inlet:

http://img.villagephotos.com/p/2003-5/191557/1986567

Phase Linear 400 Series 2; added DC protection/delay circuitry, upgraded input and output connectors; upgraded power cord:

http://img.villagephotos.com/p/2003-5/191557/1927085

BradJudy · « **Reply #25 on:** 7 Mar 2009, 06:01 pm »

Here's my latest DIY project:

I have a thread on it in the Eye Fidelity circle - http://www.audiocircle.com/index.php?topic=65646.0

mgalusha · « **Reply #26 on:** 7 Mar 2009, 07:13 pm »

I've been following your thread on the pinhole camera Brad, very cool. Quite amazing images for almost a no-tech design.

jrebman · « **Reply #27 on:** 9 Mar 2009, 04:05 pm »

I have 3 projects in progress -- one just about done, the other I have all the parts collected but need some assistance with a very dense PC board, and in the starting to gather the cheaper parts and figure out last design details phase of the third.

They are:

1.) Complete makeover of Horn Shoppe Horns. The Austrailian Lacewood veneer finished with catalyzed lacquer, the threaded brass inserts for the driver mounting screws, the threaded brass inserts for the spikes, and the BB fill hole drilled to fit the custom 2" aluminum cover plate are all done. The solid copper binding posts are mounted on plates, and the Chimera Labs 7-7 OCC Litz braid internal wiring are all here and waiting to be installed. I need to get them over to a friend's house so I can use his drill press to drill the two-step hole for the EAR Isoloss grommet for the wiring, and then the compression chamber gets lined with felt before installing the wire and drivers. Then the last step will be to felt line parts of the Horn mouth. I experimented with most of this stuff before deciding to go all out on the finishing, so the final results should be even better than the temporary tweaks.

The second project is a Millet Max Mini hybrid headphone amp, and all parts are in the house, including big black gate NX series output coupling and cathode bypass caps, and audio note tantalum output coupling resistors. Pretty much everything else is stock as called for in the BOM except for a pair of Vampire RCAs and a Thingamabob for the volume knob.

And the last project, *the* big, no holds-barred amp project, will be some variation of Poindexter's Musical Machine. Just have to decide on driver tubes and Iron, and of course come up with the money to pay for it

.

I haven't said much in the lab lately, but I've been working on these various things for quite some time now -- mostly the Horns.

I'll post pics of the whole Horn makeover process in another thread when I'm done and they are playing.

-- Jim

JoshK · « **Reply #28 on:** 9 Mar 2009, 06:54 pm »

I decided to sticky this thread, since its a fun thread and worth drooling over pictures of someone's creation. The point is to make it a gallery of pictures, and possibly links to build threads.

I am also considering making a thread on "what equipment are you currently working on?" That seems to be a popular enough sub-topic, that it deserves its own thread.

jeffdavison · « **Reply #29 on:** 13 Mar 2009, 05:35 pm »

Here's my finished mono blocks

Driver tube is a WE437a direct coupled to a EML 320B-xls using stacked power supplies.

JD

JoshK · « **Reply #30 on:** 13 Mar 2009, 05:37 pm »

Sweet!

Looks great. How does it sound?

jeffdavison · « **Reply #31 on:** 13 Mar 2009, 05:42 pm »

simply...... WOW.

JoshK · « **Reply #32 on:** 13 Mar 2009, 06:33 pm »

I'm good and jealous. What kind of speakers are you driving?

jeffdavison · « **Reply #33 on:** 13 Mar 2009, 07:50 pm »

Threw together some open baffle speakers using Hawthorne's Silver Iris drivers, I took liberties with my own crossovers (their schematic).

JD

TomS · « **Reply #34 on:** 16 Mar 2009, 03:11 am »

I think I can officially say my Behringer DCX2496 digital crossover is "done" now. If you're using one of these, especially with the Emerald Physics CS2's, you don't know what you're missing. It simply sounds fantastic now.

Many thanks to Mike Galusha for leading the way on what works and what doesn't in this setup. I've followed his journey and exchanged a zillion emails and instant messages with him. Amazingly, he has been totally patient with all of my questions and tribulations. In the home stretch last week, he even sent me a few parts from his personal stash to finish it up. This is the kind of guy AC is all about, that is, a community.

The final mod list:
- Replace analog inputs and outputs with Linear Audio (Jan Didden) remote control analog I/O board with a few tweaks
- Remove CS8420 digital in. Install Frank Oettle CS8416 clock/SRC replacement board (<2ps jitter).
- Replace 2 7805 regulators with 2 Oettle discrete mini-regulators (5v)
- Removed extra A/D converter not used on C input
- Replaced 3 AKM 4393 DACs with AKM 4396 DACs
- Replaced all electrolytics with Panasonic FM's, Black Gates, and Elna Silmic II's
- Installed LC filters on +/-15v lines
- Rewired and reterminated AES/XLR input to BNC SPDIF 75 ohm with coax, bypass ribbon cable and connectors
- Add external "Felix" AC mains filter

At this point there isn't much left to do. Most likely, the weak link is the analog output section, but I'm not sure this poor DCX chassis/pcb could take any more soldering to improve it. I think I"ll quit while I"m ahead.

My current setup is:
- Bolder SB2 - loaded, with Nirvana supply, etc.
- modded DCX2496 as above
- "Pumpkin/Shunty" balanced gain stage on LF (~19db) to provide big voltage swing to the F4's
- "Felix" built-in to preamp's remote AC/transformer box
- Balanced monoblock DIY First Watt F4 clones on LF (driven by Pumpkin)
- Single ended DIY FIrst Watt F5 clone on HF (~16db)
- Emerald Physics CS2's, bypassed binding posts on compression drivers

I'm really happy with the result and I know for sure why Mike isn't doing these conversions any more. The boards are very fragile since they were made to be built only once by automated equipment, not hacked up by the likes of me. It takes a lot of hours to do this right, and Mike saved me probably double that with his helpful tips (Chip Quik is the BEST!). I now have a huge bag full of discarded parts to show for it too.

There are a lot of mod strategies for the DCX, but this combo has to be one of the best in terms of integration of the right stuff. I really didn't believe this lowly device could sound this good, but as Zybar told me several times, indeed it does.

Bravo Mike, Jan D, and Frank O !

Tom

mgalusha · « **Reply #35 on:** 16 Mar 2009, 03:45 am »

Thanks for the kind words Tom, glad I could help. The Chip Quik does make it much less painful. I'm very happy to learn you have it back together and running. They do sound nice when all dressed up.

JoshK · « **Reply #36 on:** 16 Mar 2009, 02:13 pm »

Sounds cool Tom. It feels great to accomplish your own system goals doesn't it?

What drives the SE F4? Or did you build in a gain stage?

TomS · « **Reply #37 on:** 16 Mar 2009, 02:45 pm »

Quote from: JoshK on 16 Mar 2009, 02:13 pm

Sounds cool Tom. It feels great to accomplish your own system goals doesn't it?

What drives the SE F4? Or did you build in a gain stage?

Thanks Josh. I feel good about having almost my entire system DIY or heavily modded commercial stuff now. A pair of Abbeys would really top that off, but my budget can't handle it at the moment

There are two F4's run as monoblocks in balanced mode. The Pumpkin/Shunty preamp is set up as a fixed gain stage (20db) to drive the F4's to full output for LF from the output of the DCX. I suppose I need to get a picture so it makes more sense.

JoshK · « **Reply #38 on:** 16 Mar 2009, 03:36 pm »

Sorry, I misread the single ended ones are F5s, not SE F4s. I get it now.

Timothy Shields · « **Reply #39 on:** 4 Jun 2009, 12:07 am »

Build the Pass Labs B1 preamplifier as my first electronics project. Was quite enjoyable despite wiring on of the pots in reverse! The resulting preamplifier sounds much better than my Golden Tube SEP-1; cleaner, but not harsh and etched. I am considering building some mono blocks, but need to find a source for large heat sinks (approximately four matching 5" x 11").