ÿþ<html> <head> <title> MUSICAL MACHINE &nbsp; The Little Amp That Could </title> </head> <body bgcolor="#cccccc" background="stonebk.gif" bgproperties="fixed" ><font face="arial"> <table align="center" border="0" cellpadding="0" cellspacing="0" width="80%" ><tr><td> <div align="center"><img src="logo11.gif" /><br /> <img src="space.gif" height="5" /><br /> <h2>THE MUSICAL MACHINE<br /> THE LITTLE AMP WITH THE HEART OF AN ARTIST</h2> <img src="mmPortrait.jpg" border="2" /><br /> <b><font size="+1">In Bolivian Rosewood </p> <p> <img src="mmPortraitSap.jpg" border="2" /><br /> In Sapele</font></b> </p> <p> <br /><img src="space.gif" height="10" /><br /> </div> <p> The Machine is an ongoing (for eleven years) experiment in reducing the number of components, stages, parts, in a purist music reproduction system to the absolute minimum; in making a Lean, Mean, Musical Machine - thus its name. &nbsp;The amp circuit is absolutely as simple as technical rigor allows; a singly-driven differential 5965 is the gain / splitter / driver for a pair of triode 6V6 outputs. Source switching and volume control is onboard; no preamp is neccessary. &nbsp;The whole rationale here is to have as few devices, components, <i>pieces of wire and solder joints</i> in the signal path as possible. </p> <p> The developmental path of this amp actually was sort of spooky. &nbsp;It played like a born musician on first fire-up, and ten years down the road, all I've done to it is reduce the load on the output tubes (10K rather than 7K), draw a little more current in the front end tubes, and upgrade some parts. I would never have guessed, as speculative as this circuit was, that it would require so little development. </p <p> The result is, I think, remarkable. &nbsp;If you can live with a maximum power output of five watts, you're hardly going to get better sound at less than astronomical prices . &nbsp;Clean, clear, low distortion, ultra black background. &nbsp;High, rich, natural color of timbre. &nbsp;The virtues of SET amps are here, without the hum, power consumption, and expense. </p> <p> <div align="center"><table width="50%" align="center" border="0"><tr><td> <b><p><font color="#773377">&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; SPECIFICATIONS </p> <p> Voltage sensitivity . . . . . . . . . . . . . . . 0.8Vac<br /> Maximum output power . . . . . . . . . . . . 4- 5w<br /> Zout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2&Omega;<br /> Hum+noise . . . . . . . . . . . . . . . . . . . . . . 0.04mV<br /> Bandwidth (+0, -1dB) . . . . . . 11Hz - 49KHz<br /> Power consumption . . . . . . . . . . . . . . . .70w </font></p></b></td></tr></table></div> <p> If there is a constraint in the application of this amp, it is the lowish power and moderate output impedence, as with any small zero-feedback circuit. &nbsp;There are high quality speakers in the market that are not only quite cold, sensitivity-wise, but <i>very</i> unkind loads, dipping down to near 1&Omega; at certain frequencies, and up to 50&Omega; at others. &nbsp;On the other hand, I have a client who plays his into a pair of BBC LS3/5a's, and is ecstatic. &nbsp;I would expect that there are some volume limitations to this situation, however. </p> <p> Since each piece is made on order for the individual, input/output configurations and parts choices are to your preference, as well as such niceties as boutique connectors and a dedicated power amp (no switching or volume control) configuration. &nbsp;I do have a base model of which I try to keep an example either on hand or chassis-constructed. &nbsp;This will have a single output, and two inputs selected by a center-off toggle. &nbsp; Switches are SwitchCraft silver contact, volume control is a TKD 2500 series , tube sockets are ceramic/gold. &nbsp;Power rectification is by a 5AR4 dual vacuum diode , power supply capacitors are Panasonic TSHA and Nichicon Muse. &nbsp;Signal capacitors are Mundorf Silver Supreme or Jensen copper PIO, signal resistors are Riken and Kiwame. &nbsp;Signal wire is high purity copper or silver in teflon. The chassis rim is cabinet quality exotic hardwood, currently I have Jarrah (a dark red hardwood, see the picture of M&oelig;bius), a little Bolivian Rosewood, and Sapele, which looks a lot like Mahogany, but is tighter, much harder and denser. &nbsp;Chassis plates are [! aircraft aluminum, all fasteners are stainless steel. &nbsp;Construction is by a thirty-year guitarmaker. </p> <p> The base configuration now includes an upgraded volume control, improvements in the transformer ratings, and vacuum (5AR4) rectification, as well as some improvements to the grounding topology that reduce noise+hum down to <i>microvolt</i> levels. &nbsp;Price is $3600. </p> <p> If you would like to build your own, the project is up on the Projects side of the site. &nbsp;For those contemplating purchase, it will give you a good idea of exactly what's in the box; I keep no secrets about these things. &nbsp;Perhaps the main element of my product is the implementation skill and workmanship I am able to bring to the predicament, the developmental and parts buying savvy are yours to take if you wish. </p> <p> If you're interested in this very nice little amp, either as a client or a builder, drop me a post; my mailto is at the bottom of the page. &nbsp;Let's talk story about it. </p> <p> Poinz </p> <p> <h3> <div align="center"><a style="text-decoration:none" href="index.html"><font color="#993388">BACK TO PRODUCTS</font></a> &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; <a style="text-decoration:none" href="../realIndex.html"><font color="#993388">BACK HOME</font></a> </font></div></h3> </p> <p> <img src="space.gif" height="25" /><br /> <address><font color="993333"> Last Updated February 22, 2006<br /> &copy; and Page Development: Eric Kingsbury<br /> Email me at: <a Email me at: <a href="&#109;&#097;&#105;&#108;&#116;&#111;:&#112;&#111;&#105;&#110;&#122;&#064;&#097;&#117;&#100;&#105;&#111;&#116;&#114;&#111;&#112;&#105;&#099;&#046;&#110;&#101;&#116;"><img src="iplacard4.gif" style="border-style: none" align="middle" /></a><br /> Best viewed in Internet Explorer at 1024 x 768<br /> </address> </p> </td></tr></table></div> </body> </html>