Tube Love

How to Build a Home or Project Recording Studio that Rivals Professional Studio's Sound

http://www.tweakheadz.com/soundcards_for_the_home_studio.htm

http://www.tweakheadz.com/compressors.htm

I'm contemplating a computer setup for my home studio.

The "Academic" version of Cubase SX is available here for $349.00. You have to go through some process where you prove you are academic - hopefully working for Harvard University will do the trick...



From what I've read, the Presonus FireStation seems like the way to go to interface to my laptop. They've just lowered the price to $499 for a limited time.



FIREstation - 8x8 FireWire Audio Workstation

Features:

Two Dual-Path Tube/Solid State Preamplifiers
-20 dB Pad
48V Phantom Power
Twelve-Channel Analog Mixer
MIDI I/O
Two High-Speed FireWire™ Ports
Eight Channels of Analog I/O
Eight Channels of ADAT™ I/O
S/PDIF I/O
Control Room and Headphone Outputs
External Recording Punch Input
Mac™ and PC Compatible

So that's a total of $848 for software and interface... not bad.

www.audiogon.com

Has a subscription-based Audio Blue Book that is useful, as well as other info and classifieds.

A Dynakit PAS-2 Preamp and a Dynatuner, both stock. I got them both for a very reasonable price, esp. considering both units work perfectly. The tuner was advertised as an FM-1 tuner, but since the FM-1 is a mono tuner and the one I have is stereo I think it's really an FM-3.

Update: Okay, so now I'm pretty sure this IS an FM-1, but with the optional FMX-3 stereo adapter, available separately as an add-on.

Detailed info on the FM-1
Detailed info on the PAS-2

I haven't opened them up, yet, but they smell a bit smokey (like cigarette smoke) so I will probably get inside to remove dust and take a look at the quality of the wiring, also to see if these are factory-wired or made from kits.

There's a buttload of info on mods I can make to these, but they sound pretty great as-is. The Tuner uses a "magic eye" tuning indicator that looks really cool, and the pre-amp has a sweet sounding phono stage. I spent a few hours last night pulling out old vinyl I hadn't heard in years.

The RCA jacks on the back of the preamp are kind of crowded, making it impossible to fit modern style rca plugs side by side. Curcio makes a kit to replace the whole rca jack set, so I might consider making this mod at some point. Here's a bunch of info:

Curcio kits

PAS 2/3 Owners manual

FM 3 manual

Some more Dynaco info

http://www.tangible-technology.com/index.html

http://millennium.fortunecity.com/rollingacres/393/fun/ht/elec/audio1.htm

From: http://www.audioreview.com/Amplifiers/Dynaco,Stereo,35/PRD_115773_1583crx.aspx

If you do have or get one of these amps, you might want to try the following: change out the cheapy bluish-green coupling caps to some better caps. If I was doing this today, I would look into the inexpensive Chinese paper-in-oil caps that Steve sells at Angela Instruments (www.angela.com) as my first choice. Otherwise, try some film caps that are not too expensive. When I did this six years ago, there wasn't the proliferation of good caps like there is today. I had a choice between MIT and Wondercap. I got some Wondercaps. I didn't want to spend too much modding this amp because it's a very good amp, but not a great amp. I feel even more strongly today. You can do what you want, but I wouldn't go putting Audio Note/Jensen oil caps or Hovland Musicaps in this amp. It's just not worth it.

Also, you can change the resistors to Roederstein or Beyschlag or Dale metal film. Some people say don't change out the old carbon resistors in the ST-70 or ST-35 or the amp will sound mechanical. It's a matter of taste, I suppose. I thought it sounded more open and dynamic when I changed to good audiophile grade metal film. Even so, I still think the sound is too smooth. Don't use Holco for this, as they tend to fail more frequently when used with more than 100v through them, so I hear. Again, I wouldn't use anything too expensive, like Caddock, Vishay, or exotic carbon or tantalum films...not worth it, in my book. Also, change out the two old rectifier diodes to some ultra-fast soft recovery units.

Some ST-35 upgrade suggestions found on http://www.audioasylum.com/forums/dynaco/bbs.html:

1. Remove C1 and replace with plain wire jumper (modern preamps have DC blocking caps in their outputs.)
2. Replace C4 and C5 with a high quality .1mfd 400v. coupling capacitor. The caps in the amp are old, cheap Radio Shack Parts. Recommend (econmical) Sprague orange drop or Dayton film and foil cap or (better) Audiocap or Auricap. See Parts express or other online supplier.
3. C6 and C7 are disk ceramics which have a notoriously bad sound. While not in the direct signal path, they are in the global feedback circuit and replacing them with silver mica units (available at Antique Audio Supply on the net) should have a noticeable effect. AAS has a $25 minimum order so if you buy other parts there, it might be more practical.
4. Replace C3 with an economical .1 mfd cap. It is a blocking cap in the positive feedback loop, so it doesn’t need a premium cap, but it should be a better one than Dynaco put in there.
5. Cut or punch a hole about the size of a quarter in the chassis next to the power transformer opposite the can electrolytic. Mount a Ruby 50/50 mfd, 500v electrolytic with its mounting bracket (Parts Express 020-607 and 020-615) Use both sides in parallel as C8C. Tie the triangle and square coded sections of the can electrolytic together and use as C8B.
6. Mount a 2200 mfd, 25v. electrolytic with silicone adhesive under the chassis next to the terminals of the exisiting can electrolytic. Use it to parallel C8D.

This little amp has a superb circuit design and great output transformers and choice of tubes, but suffered from the use of cheap circuit components in the signal path due to cost considerations in manufacturing and marketing. Putting in high quality capacitors and decreasing the P/S impedance will really make this unit sound the equal of many high-end systems.

p.s. please resist the temptation to increase the value of C4&5. They are looking into a 470k grid resistance and I’m afraid increasing the time constant here will cause low-frequency instablity.

http://www.synthnut.demon.co.uk/synths_triadex.htm

There is a free Windows software "Muse Simulator" available here:

http://trovar.com/muse/muse.html

And a good explanation of the inner workings of the original Muse here:

http://www.bigbluewave.co.uk/hal_chamberlain.htm

http://www.colomar.com/Shavano/pa_speaker_project.html

I remembered a friend's Dad owning one of these in the 70's, so I did a little searching around:

http://online.sfsu.edu/~hl/c.muse.html




The Muse: a music composer machine or digital
synthesizer and melody composer, involving early
logic modules in a unique circuit that allows the
possibility of 14 trillion musical note combinations.

Manufacturer: Triadex Inc., Brookline, Massachusetts
Inventors: Edward Fredkin and Marvin Minsky
Original Price: $249 - Original Date: 1971

Their patent abstract of this electronic music composer reads as follows:

In the apparatus disclosed herein, a note generator is controlled by a long term, quasi-periodic function which is in turn generated by applying digital feedback in preselected combinations around a digital register. The register comprises means for holding a plurality of bits of digital information in a given order, e.g. a shift register or counter, the held information being changeable according to a predetermined pattern in response to input signals applied thereto. Digital feedback is provided by applying to the register at least one input signal which is obtained according to a preselectable or adjustable code from bits of information obtained from various points in the register itself. The apparatus thus, in effect, composes music as distinguished from merely synthesizing sound.

http://www.roadie.net/