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About a year ago a very good friend, Dr. Steven Rayle, a member of AC who has the fascinating knack of always selecting some of the best audio equipment I have ever heard, recommended a totally redesigned Heathkit 151A integrated amplifier in Triode mode by the master Korean audio design Sam Kim, of Sam’s Audio Laboratories, in Quebec, Canada. He not only recommended it... he raved about it. Steven uses it to drive his horn speakers. Sam’s Platinum Triode version of the Heathkit 151A has 7 powerful triode tube watts... for my Open Baffle speakers with their 97db efficiency that is “an embarrassment of riches” as Dr. Dan Mason used to say.http://www.samsaudiolabs.com/Steven and I talked about the possibility of his driving to Ojai for an audio weekend that would allow us to hear several amps, including his Sam Kim Heathkit 151A, in a kind of shoot-out on my Open Baffle speakers. Steven got very busy so that never happened.Steven’s description about the performance of Sam’s Heathkit 151A on his horn speakers began to haunt me... I trust Steven’s sense of were the magic lies in audio having shared with him several audio shoot-out weekends in which we listened to a great deal of exceptional gear and compared notes. One day I woke up thinking I had to own Sam’s creation... call it an “insight”... just a sense that this was going to be the ultimate amplifier for me and solve any integration issues I might have with my Open Baffle speakers.Sam’s total circuit transformation/re-design still uses a quad of EL 84 power tubes... but the rest of the tube compliments actually depends on which tubes Sam feels reflects his most up-to-date technical understanding of what works best in his circuit. My Heathkit circuit uses 2 pairs of 12AX7’s and 12AU7’s (Sam feels the 12AU7’s have better gain and microphonic characteristics in the pre-amp section) and a pair of 6EU7’s for the phono stage (Sam’s Platinum Triode Heathkit 151A has a phono section for those of you using LP’s as your musical medium of choice)... Sam uses the original transformers that come with the Heathkit... Sam believes that these fully-burned-in old iron transformers yield a sweetness and harmonically rich tone impossible to attain in modern transformers that have not been allowed to “age” and settle-in to their optimal musical and tonal performance potential. Sam’s Heathkit also has tone controls... and they are a dream come true... and one of the most important reasons that Sam’s Heathkit 151A is such an important and potent integrated tube amplifier for Open Baffle speakers.I have been playing Sam’s Heathkit for a few months now and the sound it incredible... the tonal range is easily the richest and widest I have ever heard on any amplifier... and I have heard and owned many of the best triode SET (and digital) amplifiers out there... the textural instrumental information has a depth, detail and precision that makes every other amplifier I have heard sound dull and recessive in comparison and there is a totally 3-Dimensional open spatial field that completely recontextualizes the space of my listening room to sound like whatever original venue the music was recorded in. Music recorded in large spaces like cathedrals actually sound like we are in a huge vaulted cathedral and the sound goes on forever. Voices sound thoroughly human, rich, articulate (no trace of sibilance or smearing) and with a palpable ripe presence that hovers into your room and pulls at your heart. The entire effect of Sam’s Heathkit 151A is that it has the speed, immediacy and dynamics that matches perfectly with the potential of my Open Baffle speakers to render music with a completely vivid, alive and real musical perspective. Indeed there are times when the musical color pallet sounds as if the music had been transformed into brilliant jewels of sound.Here are some things that Steve of Sam’s Audio Labs has said about Sam’s circuit design:“The unique engineering that goes into every Sam’s Audio Labs integrated amp is Stabilization circuitry in the power stage. The advantages are that his amplifiers are extremely reliable, extremely low variation in the power current to the tubes, so for example you will never have to change rectifier tube.Sam uses what we call Compensation Circuitry what used to be called tone controls... Sam designs his Compensation Circuity so that at 6:00 the sound is perfectly neutral and when you put it at 3:00 or 1:00 you are actually compressing the original signal so that the ORIGINAL SIGNAL STAYS PURE. All other tone control designs boost the signal 10db 20db or 30db changing and distorting the ORIGINAL SIGNALS.Also all of our units are extremely linear......Sam is a master at linearity. Sam’s favorite expressions about his circuit design is “These amps contain NO MSG”Bias to the tubes in most 6BQ5 design amps is 65 to 72 milliamps... Sam’s design is 38 to 42 milliamps while maintaining the richest possible tonal and harmonic presentation... the result is no stress on tubes, transformers, or capacitors... Sam’s amps are extremely stable and reliable.Sam’s Heathkit 151 A uses 2 separate (dual) volume controls to balance the amplifier which is the best way to attain perfect balance of both speakers.There is a great deal more I can say about our innovative circuit design but Sam and I don’t want to give away too many of our secrets... please let everyone know I would love to hear from them if they would like to speak with me about Sam’s Platinum Triode Heathkit 151A integrated amplifier. They should check out the website too to see what else we offer in the way of totally new innovative circuit re-designs for the great retro-looking amplifiers from America’s golden age in tube design.”Sam gets $2,900 for the Platinum Triode Heathkit 151A. It takes a minimum of 160 to 190 hours for Sam to rebuild his new circuit from scratch (Sam first strips the old Heathkit chassis and thoroughly cleans it). When you call Sam’s Audio Labs in Quebec Canada, you will be speaking with Steve who is Sam’s partner and contact person for all sales. Steve is a wonderful person to work with... he is a dedicated music lover and he has an unbounded love and enthusiasm for the extraordinary work that Sam does. His phone number is 514.880.3587. If Steve does not answer the phone, please call back... Steve apologized to me but said he can’t return calls on his cell phone to the USA.With Sam’s Heathkit 151A no other form of equalization is necessary for my Open Baffle speakers... they impart an entirely organic fully integrated sound to my Visaton B200 and Eminence Alpha 15A drivers hooked up in parallel (the B200’s play full range and the Alpha is crossed over at around 1200 Hz)... the bass controls set at 12:00 noon is so powerfully deep (super fast articulate bass... no bloating) that I have to turn down the bass controls or else my walls begin to shake. It is really great to be able to fine-tune the sound for each recording.Incidentally, just before I was to purchase my Heathkit from Steve at Sam’s Audio Labs, one came up for sale on Audiogon which I purchased immediately. It sounded fantastic when I received it except that the transformer ran a bit hot. Steve at Sam’s told me to send it back to him and Sam would go over the amp completely and find out why it was operating on the hot side. Sam replaced the old set of NOS EL 84 tubes with a new set of NOS RCA’s which I sent him and readjusted the bias to perfectly match the new EL 84 tubes. The Heathkit runs nice and cool now. Steve and Sam treated me with the same high level of excellent professional service just as if I had purchased the Heathkit new from them.I am finally finished searching for the perfect amplifier for my Open Baffle speakers. Sam Kim’s Platinum Triode Heathkit 151A integrated amplifier is a dream come true.With Warmest Regards ~ Richardhello i am useing quad classic ll an old 2 mono block with my open baffle (altec 605) and i like to know if quad 34 pre- amp can mathing the ampl regards ezra