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The TJ Meshplate (2.5V 300B) should work in the circuit and may have a bit more high end. The "rolled off" sound could be more the absence of distortion than actual lack of high end. But maybe the TJ has a lower impedance at higher frequencies .. or something. I have been very happy with the Sovtek 2A3, but using the small parallel feed transformer provides excellent high and low extension. I've pretty much lost track of what a standard SET transformer sounds like. Leo

Crown D-45 is designed for efficient speakers. Low impedance out and excellent low power capability (no harshness, very neutral sound). If 20 to 30 Watts is enough for you (I use a fraction of that) the Crown is an inexpensive winner. Crown D-75A is supposed to be as good but with a bit more power. I haven't tried it. Other Crown models .. I've had a few bad experiences. Others here like a few of what is available. Leo

That would be my take on the two players (AH and HEART). I wonder how the AH gets the low impedance, possibly cathode follower. Leo

Erik, Very nice amps and a great deal for he new owner. Leo

Belkin filter URL: http://catalog.belkin.com/IWCatProductPage.process?Merchant_Id=&Product_Id=100991

I don't have specs for a tubed cd player, but if the output impedance is over 1KOhms I wouldn't expect the best out of the combination. Even at somewhat lower output impedances I would recommend a serious audition. Leo

MojoX, A power line filter (I use a Belkin F5C980-TEL, $80 at Staples) may address the " .. sometimes could be warmer." There's a lot of rf on house power and it gets into amp circuits and modulates the audio which imparts a slightly "electronic" or un-natural sound. Leo

Possibly the 83s needed breaking-in. I've owned RF-7s since they were introduced and don't listen at high levels. I always thought they sounded somewhat reserved and colored compared with my Chorus-IIs. About a month ago I subjected them to about 20 hours of sinewave sweep from 20Hz to 20KHz at a level that produced about 1/4" cone excursion at 20 Hz (obviously the power dropped significantly at the higher frequencies or I would have blown the hf driver). The coloration and reserved quality is gone. I've always liked the high end clarity of the RF-7, but now find they have a very natural and dynamic presentation. I wouldn't be surprised if the RF-83s would improve significantly after a similar workout. Leo

Crown D-45 is very good and not expensive. Leo

Jazman, Jeff's parallel feed design with Eriks added ultrapath is a substantial change from the Moondogs' more traditional approach. Will be interested to hear your review. Beautiful amps. Leo

Scott, The previous cartridge was a Grado Gold. Leo

Thanks to some prodding from maxg and wolfram I upgraded the cartridge in my Basis 1400 / Graham 1.5 / Creek OBH-8SE phono chain. Goodwin's High End is right up the street from me so I asked their opinion (prefering to support the local audio store if possible). They recommended a few alternatives, I did some research and settled on a Benz Micro Ace, high output (blue). Goodwin's charged the same rate as everyone, but installed the cartridge for me (I think that's a big deal because I just don't have the equipment or knowledge). Brand new, the Benz has transformed my record collection into a music collection. The ability to hear different violin timbres, something I find important, is now in the vinyl domain. Dynamics, frequency extension, detail, accuracy .. all vastly improved. Max and Wolf, thanks for the push. Also thanks to others, like Kelly, who tried to push me in the past. Leo

Marty, If you get yourself a sufficiently sophistocated low pass filter (with adjustable cutuff frequency and amplitude) for the sub, you can leave the Heresys connected directly to the amp sans crossover and adjust the low pass so the sub fills in below the mains without intruding on their territory. Leo

silversport, Transistors are exponential devices. They produce some very unpleasant distortion products that are minimized using feedback. Feedback has a few problems of its own and is also least effective at low output power. What you are noticing using the HF-81 is that your KHorns operate at low power (where transistor amps tend to be their worst). On the other hand, tubes tend to be more linear (triodes more linear than tetrodes or pentodes) and the distortion they do generate tends to be less irritating. Tube amps also produce their lowest distortion at low power. With efficient speakers like the KHorn, low distortion at low power is the key to a more natural sound. Transistor and digital (pwm) amps can be found that rival the good sound of tubes, but one has to be very selective. Leo

Steve, When I get home I'll get the Manze titles and numbers. The "richness" I was refering to is the sound of the Amati violin (built in 1690) that he sometimes uses, and did use on the recording of Pandolfi sonatas. The Manze Harmonia Mundi recordings themselves are some of the most difficult I've encountered. For some reason they really illuminate system flaws. Leo "Andrew Manze Portrtrait" HMX2907278 excellent sampler collection. Top recommendation. Phantasticus "Romanesca" HMU907211 music by several 17th century Italian composers Handel - Complete Violin Sonatas HMU907259 (very difficult recording, incredible music) Pandolfi - Complete Violin Sonatas HMU907241 (one of the most beautiful sounding violins) Corelli - Violin Sonatas HMU907298.99 (I like Corelli, If you want more v. sonatas, this is good) Based on the sampler and a few of the others you'll know where you want to go. All Manze's recordings (and performances) are great.

Wolfram, Can I use my Creek phono pre with the Garott P77? The load impedance looked a bit low on the Needle Doctor website (47 Ohms) but maybe that should have been 47KOhms. Leo

Looks like a nice improvement. Dean's crossovers are a good move. RF-7s are a great speaker. Leo

Hi Erik, By the way, Erik encouraged me to try the "ultrapath" cap to clean up the high end detail. I liked it so much I went on to parafeed. Then it was Eric again who suggested I try removing the 2A3 cathode cap. Technically it made sense but Erik had to push me pretty hard to get me to try it. Once that change is made output audio current stays completely out of the power supply electrolytics. To do it, the "ultrapath" cap has to be big enough to handle the lowest frequencies the amp will deliver. Anyway, the grid stopper: I thought I had it right on the grid terminal. Is that what you mean? I'll check my notes. I didn't think there was an option. Larry, Is the Graham 1.5 heavy enough to handle the lower compliance of a moving coil cartridge? I am a complete novice when it comes to tt setup so it's going to take me a while to come up to speed. Leo

TheSevens, The Music Hall Mambo looks interesting. Let us know how it sounds. Also, if you don't have a power line filter I suggest you get one. The Belkin F5C980-TEL (may still available at taples) is inexpensive and effective. Leo

Congratulations on the Moondogs. Nice amp. The Sovtek 2A3 is about as good as it gets. The old RCA's probably do a tad better, but it's not by much. I have the same RCA 6SN7 driving my Sovtek that Jim mentioned above. I also have the Sylvania, which I like to pair with the RCA 2A3s. I've had the Sovtek/RCA pair in there for months and have no motivation to change them. Enjoy. Leo

Max and Larry, The tweaks all positively influenced violin reproduction and were always motivated by some problem with the sound. There were plenty of ineffective changes which I removed when they didn't work. Obviously I haven't included them in the list. A few examples of problems and related fixes: * Weak lower midrange on the RF-7s caused violins to sound thin. The aggressive break in effectively addressed that. Since I don't listen at loud levels I had never really broken the Rf-7s in. * There were a few persistent system resonances that would cause certain high loud violin notes to be way too loud and lacking in timbral consistency. The resistor across the output transformer addressed that problem. It was one of the hardest things to track down and several other attempts had failed. * RF filtering (power and power supply) removed a harsh an gritty texture that would accompany louder bow sounds (when the bowing is started or stopped for example). Sometimes there would be a pronounced swishing sound accompanying changes in bowing direction that affected violin and even more: cello. All other instruments and vocals benefit from the changes, but getting violin right was the main motivator. The bass in CSN&Y "Carry On" just came to life after the RF-7 break in. Both of you have better record playing equipment than I do. My equipment is a Basis 1400, Graham 1.5 arm, Grado Gold, Creek OBH-8SE. Violin sounds very good, but lacks the timbral accuracy of the CD and SACD source. Also, when things get really loud and complicated there is some obvious intermodulation that doesn't exist in the digital sources. I'm aware that this doesn't have to be the case and one of these days I should improve things .. probably cartridge and phono pre? Leo

Additions: SET output transformers are wound for 4 Ohm load. RF-7s and Chorus-IIs are on spikes Air core inductors replaced ferrite core devices in the RF-7 crossover ---------------------------------------- Notes on getting the most out of violin recordings. Playback volume is never louder than what I would hear in an acoustic setting 10' to 20' from the instrument. A violin can be very loud and at times piercing. If volume is louder than life it's probably going to hurt and it's not a realistic measure of the system's ability to reproduce the sound. I regularly attend acoustic events involving solo, several, and/or "massed" violin(s) and what I hear at those events is what I try to reproduce on my systems. There is a tremendous variety in violin sound, from instrument to instrument and player to player. For a rich, woody tone I like Andrew Manze (especially his 1690 Amati on the Pandolfi Sonatas), Gil Shaham on "Schubert for Two," and Jascha Heifetz on the Sibelius/Prokofiev/Glazunov Living Stereo SACD. Most other recordings don't sound as rich, but in real life, they don't either. I've heard Manze at that 10' to 20' distance and his recordings are pretty accurate. What I've done to get it "right" on my systems (somewhat in order of impact): Amplifier: Has to be able to produce milliwatts with low distortion. Low distortion at low power has to be the focus of the amplifier's design. I've had luck with the amps listed below. This may involve a compromise. I don't like the way my no-feedback tube amps accent the Chorus-II midrange, but they're great with violin. If I want smooth frequency response I use the Crown. Speaker: Use high quality caps in the crossover and Voltage condition them before installation (Voltage conditioning is applying, in both polarities, DC at 100V or 2/3 the cap's rated Voltage, whichever is lower). I prefer my RF-7s: I find the high end much cleaner. Power: Use a decent Power conditioner .. one that filters out rf. I use a Belkin F5C980. Source: It has to be clean. As a rule, garden variety op-amp buffers won't work. All my sources are class-A (op-amps or discrete). I did upgrade the power supply cap in my Philips 963SA and that was very effective. I don't know if that would have been as necessary if I had been using the power conditioner at the time. The sound is obviously never going to be better than the source so you have to pay attention to what you use. In my Sonic Frontiers "TransDAC" I've upgraded the op-amp buffers to the latest from Burr-Brown (owned by TI). Tweaks:-------------------------- In the RF-7s I slightly reduced the resistance in the horn midband shaping circuit. RF-7 break-in. I used a 20Hz - 20KHz sweep (reduction in power with frequency) track 18 on the Boston Audio Society "Test CD-1" and let it repeat all day, 2 days in a row (about 20 hours total). Using a sine wave doesn't require much power to get substantial driver excursion. I think the cones were moving about 1/4" at the lowest frequencies. Be careful with this, but it is effective. I had to use earplugs when setting it up and even going into the room to turn it off. Crown D-45: stock, and remarkably close to the SET. SET (my favorite for violin): Started with a Moondog. Removed 1st stage cathode cap. Now using Hovland musicaps for interstage. change output to parallel-feed removed the 2A3 cathode cap and used a big enough (Solen) "ultrapath" cap to go down to 10Hz. Added high value resistor (can't remember the value) across the output transformer primary to damp ringing. added grid-stopper resistors on all tube stages. PP: This amp pretty much reflects the SET approach but in a pp config. Gain/phase inverter is a differential config. with true current source. Magnequest transformer. The transformer is usually used with EL84 tubes, but since I'm using the KT66 (or actually 350Bs right now) in triode, no feedback mode I prefered the smaller size, higher input impedance (lower output impedance). Tripath PWM: The P6D's major tweak is removal of the input cap and general use of high quality parts. (Don't remove the input cap on other pwm amps, some additional power supply changes are necessary to make this work.) Minimal active stages: I don't use a pre-amp. I use a resistor ladder type attenuator. 1/2M decent quality cables. However all my amps develop full power with 1Vrms in. Some amps need more drive and a pre-amp is necessary. Just don't have any more active circuitry than absolutely necessary. No tone controls. Signal Cables: I prefer cables that use two conductors (something approximating Litz construction) for signal and reference with the shield connected at only one end. It's a more differential treatment of the signal. Speaker cables: Again, I prefer something approximating Litz. I'm using Audioquest "GBC Delux SST" from HCM Audio. That's all I can think of for now. If I think of anything else, I'll edit this. By the way, while writing this I've been listening (through RF-7s, SET, Philips) to the Shaham and Manze disks mentioned above. Beautiful, natural violin sound and absolutely no listener fatigue. It can be done. Leo

I'll go ahead an post the list. It will take me a day or two. Leo

D-MAN, I've been working on cleaning up violin reproduction for years. I've found numerous sources of distortion and resonance that contribute. The grid-stopper that Erik mentioned is one of about 10 (maybe more) contributors. I just found them, one by one and fixed them. If you want I could make a list of all the possibilities I know of and send them, or post if people are interested. Now I can listen to string quartets, piano quintets, trios, etc. and hear the music and expression without the distraction of little electromechanical oscillations and gratings. I suspect, in the end, even with the best of equipment, some final work is required to remove various application-specific interactions between the components. Leo

Rick, When I installed spikes on the Chorus-IIs I placed 2 in front and 1 in back. Also, I didn't install them on the riser. I built up the area behind the riser so that when the speaker is on the spikes it looks like it is on the riser .. you can't see the spikes. Leo