CLASS IX - L622 VACUUM TUBE POWER AMP - 20WPC RMS - NEW Start Price USD 799.00 Current Price USD 799.00 Time Left - Bid Count 0 Buy It Now Price - Reserve Price - Start Time Tuesday, August 26, 2008 End Time Tuesday, September 02, 2008 Location St Catharines, Ontario See more about 'CLASS IX - L622 VACUUM TUBE POWER AMP - 20WPC RMS - NEW' Description New Page 1   L622 HIGH FIDELITY VACUUM TUBE POWER AMPLIFIER Note - photographs may take some time to load. Be patient.....it's worth waiting for! Completely hand crafted excellence. I build about 8 to10 of these per year. Unlike the majority of amps I build, this one hasn't found a home yet, so I can offer it on Ebay. No, this isn't one of those amps that you want to run an iPod through or connect to your computer. This amp invites you to complement it with a high quality preamp to get the most bang for your buck. Go ahead, run a high end source and tell me what you think. I know you'll be well pleased. I'll put it up against anything in it's power class. Yes, it's that good. At a fraction of the cost of any comparable commercially available, or even custom hand made, amplifier. Scroll down to read more about this wonderful piece of audio excellence. This amp is supplied with Sovtek 12AX7's. Not the long plate LPS versions, but the short plate jobs. The Sovtek 12AX7 short plate is a highly under-rated signal tube that presents extremely low noise and very low microphonic characteristics.  No doubt you will want to roll some different tubes. I suggest vintage Telefunken or RCA tubes if you're going to play around. Stick with 12AX7's though. Anything else will affect wave symmetry and increase THD. The output tubes are a matched quad re-issue Tung Sol 6L6GC's. This is the first time I've tried these and the results are very impressive. I was able to reduce THD to 0.9% at 10 watts RMS per channel rising to no more than 1.4% at full power at 20 watts RMS per channel. These tubes really bring out the detail in vocals and acoustic instruments, yet they're punchy when they need to be. The frequency response is excellent at 30Hz to 25KHz at +/-0 .5dB falling to -2dB at 20Hz. But these are just numbers. The real test is in listening. The sound is breathtaking, satisfying. Open and airy mids and highs, deep accurate subsonics, controlled punchy and well rounded bass.  It'll sound a bit darker with EL34's. If you prefer jazz, classical or folk, stick with the 6L6 family.  When the JJ's in my own amp wear out I'm going to put in a quad of the Tung Sols. And yes, I use negative feedback and I'm not ashamed to say it. Most amps do use NFB to reduce THD and also to help in backing off open loop gain. This is a paraphase class A push pull design. The paraphase front end keeps the circuit very simple allowing the character of the tubes to be fully appreciated. The output tubes are in a self biasing configuration. No bias adjustment means you can pop in a new set of 6L6GC's or EL34's without having to mess about with finicky bias adjustments. "Plug and Play", if you wish. Input sensitivity is 1.5VRMS input for full output power. Ths means you'll need a good preamp to get things rolling. The perfect companion for this amp is my AP1 vacuum tube preamp modeled after the famous Marantz 7C. If you want, I can forward some photos of this preamp and keep you in the loop with respect to availability. I build these to order with or without a MM phono section. Did you notice the 2 LEDs on the front panel? These are full power indicators and will light up when either channel reaches full power. This is helpful if you want to run the amp at it's peak performance. I like to run with the LEDs lit no more than about 5% of the time on loud passages. These will let you know when the amp is getting beyond it's 1.4% THD level. I guess you could compare these to clipping indicators on solid state amps. This is a feature you won't find on the greater majority of vacuum tube amplifiers. The LEDs are controlled by a comparator circuit that monitors both positive and negative waveform peaks. This handy feature will warn you when you're driving too hard thus helping to extend the life of your output tubes. The base measures 15.5" wide X 9.0" deep X 2.5" high. The chassis is constructed of 0.050" aluminum. Top and bottom plates are 0.090" aluminum. Standard 6-32 and 8-32 fasteners are used throughout. No metric stuff here, just good old fashioned American nuts and bolts! Solid, non-ferrous construction reduces EMI and magnetic fields. Holes are punched, not drilled. I own a 7.5 ton punch press and a box and pan brake, so there's non of the regular jagged holes and crooked cuts that you'd normally get in a handmade chassis. The finish is high heat baked powder coat. Very durable and easily cleaned with a mild soap and water solution. The wood side panels are mirrored cut red oak finished with tung oil. These double as handling edges so you don't get fingerprints all over the metal panels. Hammond transformers are used exclusively. Hammond is one of the oldest established transformer manufacturers in North America with a solid reputation for building transformers that last for years on end. This photo below is of the interior of the amplifier. High quality parts,  single point common ground, and expert build methods yield a dependable low noise circuit that will last for generations. Hand made power supply printed circuit board is heavily tinned - no exposed copper traces to corrode over time. Balanced AC heater supply is capacitor bypassed so that no hum is present at the output. Solid state B+ regulation yields zero ripple supply voltage at low impedance to the 12AX7's. The result is an astoundingly quiet background rivaling the most sophisticated solid state amplifiers. The over sized power transformer and 4X330uF bulk filter capacitors supply more than ample current to allow the output tubes to do their thing without restrictions. When the tubes want current, it's there in spades. This is the primary reason for this amplifier's impressive bass response. Go ahead, connect a mid efficiency pair of speakers and have a lease-breaking party! You'll be able to play for hours on end without compromising sound quality. Try a pair of K horns. WOW! Don't let the low price fool you. This is truly an audiophile quality piece of equipment. Output impedance selection is easily performed by moving printed circuit shunts at the amplifier's output terminals. Choose 4, 8 or 16 Ohm output impedance. Output terminal printed circuit assemblies are labeled for easy identification and quick configuration. So what do you think? Are you ready to own an excellent amplifier? Are you ready to "jump the stump"? Or are you just going to item watch while this amp slips away on you? My regular price is $899.00. I'm going to sell this one for $799.00 and include free tracked and insured shipping to anywhere in North America. Can I build one for you? The next run of L622 amplifiers will be ready at or around the end of October 2008. I am taking orders now. Find out how you can own one with easy payment terms. Send an email to me using Ebay's message system. CLASS IX and the CLASS IX logo are registered trade marks C2008 of Ken Stapleton. All rights reserved. Place a Bid!