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My buddy John came for a visit. He's the guy who bought me the SCA80Q and the kits from you. We did some serious listening.
First we compared the GT-101 with my Hafler DH200 with Musical Concept mods. The Hafler is over 30 years old, but still sounds great. We started with the Hafler playing Etta James, "Mystery Lady". This is a very well recorded disk arranged by the great Cedar Walton. It sounded great. We switched to the GT-101. "Wow! That's different!" John said. "I hate to use all those over used adjectives, like open, transparent, more air between the instruments, and tighter bass. But there it is." We continued with Frank Sinatra, Ray Charles, Little Feat, Loggins and Messina, and finally "Pictures At An Exhibition". John wanted to like the Hafler better. We both had Dynaco Stereo 400s many years ago and still have great affection for David Hafler and his products. "There's no denying it. It's just a better amp." John said.
We went out for breakfast and I discussed putting the Updatemydynaco amp kit in my SCA80Q. He said by all means you should. When we got back he wanted to listen to the SCA80Q. We took the speakers from the family room to the office so we would be hearing the same speakers, in a smaller room, but same speakers. He loved it. How can this small, old amp sound so good? It has the Updatemydynaco power supply cap upgrades, but everything else is original. "Should I replace the power supply and power amp?" I asked. "No, leave it alone. You already have the GT-101, this is a different flavor. You don't need 2 amps that sound the same."
True. Nothing sounded bad. The GT-101 has more a detailed transparent sound. But all the amps sound good in their own way. I am looking forward to my next kit. Replacing the components on the SCA80Q's preamp or maybe power amp upgrade, or Pat-5 phono upgrade. Maybe you could offer a complete component replacement for the Pat-5's main boards and modify the Pat-4 phone board for use in the Pat-5.
Just an update to let you know I like the GT-101 more every time I listen to it. And now I have John's opinion to confirm my impressions. John's amps are a AVA Dynaco Pas-3, McIntosh MX112, totally restored Dynaco Mark 3s and a restored McIntosh MC225. John knows good audio.
Keep up the good work!
All the best, John
Sent from my iPad
I wanted to send a quick follow-up to let you know that I'm 100% satisfied with the GT-101 kit. The instructions were one of the best technical step-by-step documents I've ever followed - extremely clear, accurate, and covered every step very well. And the sound is fantastic! I'll definitely recommend it to my friends & family.
I was initially reluctant to undertake the building of this kit, as it had been over 40 years since I had actively built the Dynaco kits! However, I did and I am really glad I did! I had more fun doing this than most anything I have done in years. In fact, my wife was so impressed, she insisted on giving me the fully-loaded preamplifier kit for Christmas!
Seriously, the kit directions are absolutely spot-on. The very few questions I had were all answered within 24 hours by Dan himself! Man, talk about service!
As it had been so long since I had done any soldering, a friend of mine with a Master's degree in electrical engineering recommended that I practice soldering and especially desoldering on an old amplifier that did not work. This was really worthwhile and highly recommended for the enthusiast who has not done any kit building in a while.
I did purchase a few things that really aided my experience, partly age-related! I got a 16X LED magnifier from Amazon that really helped me in reading the numbers off of diodes and discerning the colors on the resistors. Also, I found it invaluable for examining each solder joint. Through it, I was able to determine a few cold solder joints that might have jeopardized my kit. I also purchased a PCB holder that was very helpful in all my soldering of resistors, capacitors, diodes, and transistors. I also got a magnifier with an LED light and a headband. I found that using the 3.5X magnification ensured excellent soldering technique. For desoldering, I used both the copper mesh and a suction desoldering device. I do recommend a very high-grade wire stripper and a wire cutter that will cut very close to the solder joints when removing the excess "legs" of the resistors and diodes.
Now, for the way it sounds: I had passed the tests Dan recommended before, testing the voltage of the transformer and the decreasing voltage at the speaker terminals. Afterward, I hooked it up to a rebuilt Dynaco FM-5 tuner and a Dynaco PAT-5 preamplifier, all running through re-foamed and recapped AR-4ax speakers. I thought this was a great merger of the new (kit) with the old (40 year old Dynaco and Acoustic Research components). Previously, I had used a completely rebuilt Dynaco ST-120 amplifier, so I thought this would be a good test for the GT-101.
Well, you have to hear it to believe it! It sounds amazing; it was like a veil had been lifted from my system what with the revealed clarity. The dynamic range is amazing as is the overall quietness of the amplifier. The bass output is much improved. In short, this amplifier behaves like a much more powerful system and certainly a system costing many, many times more!
All-in-all, Dan has really hit a home run with this product!
Hi Dan, Well, I must say that you do an excellent job with your Akitika endeavor. I've built a lot of kits over the years..Dynaco, Van Alstine, Bottlehead, Latino, Mottram, etc. I've dealt with missing components, poorly written directions, etc. Your kits are perfect in that regard, no missing parts and excellent and concise directions and illustrations...very nice! Best regards,-Art
Received the kit in only three days of ordering, fantastic service. After about sixteen hours over several days it was done, tested without any smoke, heat or explosions. Put into my audio system and very smooth, detailed, open sound emerged from the start. The kit was such a pleasure to build, but my wife was disappointed it didn't take longer! Meanwhile, with about sixty hours of use the sound has improved to a very smooth, detailed, open sound stage, tight articulate bass and amazing amount of power given its specifications.
All my electronics have been tubes for decades, and this is my first solid state amp. It is an amazing sounding piece, and without doubt a great value. Many thanks again for making an excellent instrument.
I just finished assembling my kit. It went together very nicely. This kit met all my expectations for build quality and design. I love the chassis! Nice and compact. I am a engineer (mechanical) and it's obvious that a lot of attention to detail has been put into this amp design. I have built a lot of hifi kits, both tube and solid state so I have seen the gamut of kits.
The sound of this is fantastic as well. I am working on a small room system which is using some small diy high resolution monitors with sub and DSP. I tried one of those cheap Chinese Class D boards. I couldn't listen for more than about 1/2 hour before my head started hurting. The GT101 turned it into a high end system.
This is my first chip amp project. It seems like it is in vogue to make implementations that are totally stripped down bare bones designs (lab 47 clones and less). Your design seems much more complete with capacitor coupling on the output and all the other caps and inductors not to mention a regulated linear power supply. It sounds great and I don't have to worry about getting my speakers fried if some mishap occurs.
This amp kit is a fantastic value and gets my highest recommendations.
Well I am through with the build. sounds pretty good from the get go. I will let it burn in for a while. and it should sweeten up after 100 hours or so. My Alons are 6 ohm speakers the bass is pretty good. I did all your recommendations for sinking the sinks to the chassis. Might not have to monoblock it and build another. This kit was a pleasure to build. Keep up the good work!!! Yours David
I have built many kits (as we have talked about). I really enjoyed putting the GT-101 together. great instructions, didn't have any left over parts. Ha! Ha! I find myself digging out old vinyl Because this amp is so detailed and open. It has crisp airy highs and tight bass. I was afraid it would not produce bass because of its lower power rating. This amp keeps reaching out more as it breaks in. I left it on for 36 hours (some electronics can get cranky if left on) It produces no heat at idle. Its probably not throwing more than 2 watts!! (Dan's note: each channel takes an idling power of about 4.5 Watts) It only gets a little warm with play. It is super quiet. my Perreaux 2150B buzzed a little enough to tell it was on, but not the GT-101 I have to see if the light is on!! its so quiet. What a noise floor...It drives my old Alon 5's with ease. The sound staging is bigger. This is an amp to be proud of. This is truly an audiophile piece of gold for less than the price on a box set of Beatles records. No, Dan did not pay for this love festival... This is D.P. a music lover who likes great stereo gear!!!
P.S. I will probably buy another and try bi amping. David
Keep designing well..David
As you know, I have different amps, McIntosh (SS and tubes), Dynaco (Bob Latino ST-120 tube amp) and even Lyngdorf semi digital amps... When listening to the GT-101 I do not miss any of them..... I think that's the best description about its sound, which is fabulous! When listening to John Lee Hooker or Stevie Ray Vaughan, it drives my Tannoys (91dB/W) to "thunder & lightning" . Just great!
"Hi, Dan. The kit got here quite quickly, given the distance. I got it on Thursday and finished it this Saturday morning.
The kit was very nicely thought-out and designed, was packaged very neatly, and it assembled quite easily.
The sound quality is far better than I'd actually hoped. Two friends and I ran these through Polk Audio LSiM 703's, Mission 753f's, and Omega Super 6 Monitors.
The amps were an old NAD (I can't recall which,) two Monarchy Audio SM-70 Pro's as monoblocks, and the brand new Akitika GT-101.
In a nut-shell: the NAD was just old, maybe poorly maintained, and didn't do well at anything. A single Monarchy in stereo couldn't compete with the Akitika.
Even running both Monarchy's in mono weren't quite as enjoyable as the GT-101. The only place the Akitika didn't win was at separation, but it took a pair of monoblocks to do that. It easily beat a single SM-70 Pro's separation.
I hadn't really wanted your GT to better my Monarchy's - I paid a fair amount for them - but with each pair of speakers we used the Akitika was a better match; it just rocks with the 94db single-driver Omegas!
I'm glad I built this! Thanks for designing it, Dan. I'll be showing this off to everybody I know!
And a postscript: I've been using the GT-101 to drive a pair of Mission 753f's for the last few days and they're the best pairing yet! I haven't even turned the volume past 50% and we're in a medium-large room. The amp needed to burn in a bit - for the first 20 hours the was a "nasal" quality to the amp, but that passed some time ago. The bass extension is great! The highs are nice and smooth, but still revealing.
The GT-101 also runs surprisingly cool. Even at half-volume for 4 hours the vents never became what I'd call warm. That will be SO nice come summer! Now I guess I'll just have to hope and wait for an Akitika pre!
Thanks for everything, Dan!
" I just finished installing the GT-101. It replaces a Dynakit Stereo-150 in which I fried one of the channels. I also replaced the Pat-4 preamp with one in which I installed all your updates so far. Let me say that the sound is superb, better than before! Smooth comes to mind as well as taught, no ringing that I can hear. This is most likely due to the low IM distortion and of course the good damping factor. I doubt that I can hear Harmonic Distortion at these low levels, even in the previous set up with 0.5% HD or so I couldn't. The harshness in the sound that I associate with IM and crossover is not there anymore.
The assembly of GT-101 was straight forward, easier than the PAT-4 up dates even. Your instruction manual is excellent, better than Heath or Dyna. The quality of the parts looked to be very good with a very nice chassis. I am looking forward to additional Pat-4 updates. Hopefully with enough oomph in the last stage to drive 30-60 ohm headphones! "
"Hi Dan..Here is some feedback from a happy customer. I just finished my first GT-101 today. A lot of things have been delayed by our move to another city, but I finally got around to your kit about a week ago. It was a straight forward build if I just took my time and double checked as I went along. Anyway, late today I hooked it up to my old Dynaco speakers and was very impressed. It sounded great and gave me a new respect for the speakers which I had not tried in some time. I tried jazz, bluegrass and classical at high volume for some time and the amp never broke a sweat. It sounds great. I'm putting together a DIY speaker kit and both will go to my oldest daughter. Then I'll get going on the second 101 for another daughter. There may be two more after that.
I really appreciate your work and the pleasure the 120 rebuild and this kit has brought. Your kits and upgrades deliver a lot of sound and pleasure for the buck. I hope you continue.
An aside...just as it was testing for the 72 volts I bumped a nearby table with my back side and a book hit the floor. Like to have scared me to death! I just knew everything was going up in flames. Fortunately all was good and the dc voltage came in at 72. Thanks again for the good products and support."
"I ordered your GT-101 kit several weeks ago, and I'll never look at a soup bowl the same way again. Nor will I ever plug in an appliance without keeping my right hand in a pocket. Great kit! Great assembly manual! Great sound! Your advice to step away from the kit when tired should be applied to all lines of work.
Once I had assembled the kit, I started taking a closer at it. Much better inherent quality than the Dynaco kits. Take the case, for example. Dynaco: self taping screws. GT-101: integral welded nuts for the threaded and counter sunk flat head case screws. You can take apart the GT-101 case as many times as you like. No pointy corners on the GT-101 circuit boards because they've been trimmed plus you get real metal lined through-holes that do a great job wicking up solder. With a good quality soldering station tool, anyone should be able to finish those circuit boards so they look professionally assembled.
I took a few liberties with the kit. I glued in place the top run of each six loop output inductor with a few dots of super glue. Treated the assorted lugs with shrink wrap tubing to cover the solder. I used a guide pin to help install each of the three heat sinks after applying the white heat transfer paste. So, no mess anywhere inside the case. And last, I found that lining up all the resistors on a piece of white paper in the install-order from top to bottom on the paper really made things move along quickly."
"Finally got a chance to build the amplifier. Thanks for the enjoyable experience, the clear instructions, and the great value. It took about 8 hours and I work slowly and deliberately. It sounds great given the very reasonable cost. I know it would be a big project, but if you design a companion preamp, let me know. I would definitely be in the market for another fun kit. Thanks again."
So I have been listening for the last 2 evenings to this amp. It is a good sounding amp. If this was the only amp I could have, I would have no regrets assuming the speakers were appropriate. The price/value ratio and the extensiveness of the kit are tough to beat. The closest ClassD can come is around $385 before shipping ($185 for their 60wpc kit + $200 for their case with all bits). I'd like to hear them back to back. I have given it the thumbs up to the folks I know who were interested. The other components were:
I have since tested the amp with Large Advents, which the Akitika drove quite well.
"Dan, good afternoon. Just to let you know that I finished the assembly of the GT-101 today. Power supply tested at 71.4 VDC and speaker binding posts testing performed very well. I played some music in the testing jig I assembled with some small high quality speakers I have here and the equipment performed excellently.
Of course, I do not have specs testing equipment such as frequency response, power output, channel separation and all that crap. But my ears are still working fine and the heat sinks were slightly warm, which of course is normal due to the volume I was playing the speakers, but the prognostic performance is of a very stable, very well designed, high quality components and the assembly manual is impeccable.
Of course, there are tiny details such as –for a person, novice, who needs these, of course-- when the instructions for connecting and soldering the black and yellow wires from the transformer into the X1 and X2 at the Power Supply board, something could be said to the effect that either of the two colored wires [black and yellow] can be connected and soldered into any of the two connection sites [X1 and X2). Just a comment, though, nothing serious.
But, to be honest to you, I believe that this kit will be a success and you will be selling a lot of those. The cabinet is very simple and functional, but precisely accepts every bolt and board at its exact place very beautifully. As soon as I have some funding, I will very probably order another kit...
In short: This extraordinary equipment, very reasonably priced was a lot of fun to assemble it. I really enjoyed working it."
"I finally had a chance to get to the GT-101. In short a beautiful and very high end execution of some wonderfully updated classic design insights. I have included some photos of the build. Excellent components and well-conceived isolation, and amplification. I have changed some cable routing and star ground a bit but all very minor tweaks...beautiful sound, great S/N ratio, quite transparent. Congratulations."
"Disclosure: Aside from being an electronics genius and a nice guy, Dan Joffe is my cousin. All the same, I call them like I hear them. I have been tinkering with speakers for about a dozen years and also build high end interconnects. I take audio seriously, probably too seriously, but I digress.
Many reviewers speak in the arcane secret language of audiophilese. They define performance using words to represent concepts that are not clear. Moreover what sounds good is subjective. So, instead of reviewing gear with words like sibilance, attack, decay, tempo, sheen, airiness, flatness, punchiness, etc. I ask a more basic question. Does the damn sound coming out of the speakers sound like real music? You will never hide the Lincoln Center Orchestra in a pair of speakers, even really big ones, but I think you get the drift. Certain instruments tend to be particularly telling on the quality of a system. To my ear piano, violin, brass, and the female voice tend to represent a solid portion of what separates good gear from excellent gear.
The GT-101 has a very nice musical nature. It sounds even top to bottom, not favoring or limiting any particular frequency range. One of the criticisms of the original Dynaco solid state amps was that the high end would get a bit shrill. This is not the case with the GT-101. I listened at all volumes from low through ear-bleed and the high end remained detailed and musical. One of my reference tracks is Take the A Train performed by the Lincoln Center Orchestra. The piano in the opening has a wonderful reality about it and when the brass kicks in later it just sounds right. The sound is textured as in a live performance and the instruments remain distinct, not blended together in a music mash up.
The GT-101 held its own compared alongside several other (more expensive) amps I auditioned over the same time frame. For its very modest cost it is a steal. I would recommend the GT-101, not just to Dynaco junkies, but to anyone who appreciates good music and excellent value.
Building the GT-101 kit was fairly easy for me and it worked right out of the gate. Again, disclaimer, I have quite a bit of experience assembling amplifier boards so it was not a new experience for me. I have built several other kit amps in the past few years. The quality of the provided directions with the GT-101 is just far and away the superlative winner. Read the next sentence carefully. Any patient person with steady hands, a $10 multimeter, and a $5 magnifying glass can successfully build this kit."
Rob from Oregon:
"...the next track utilized is from Genius Loves Company (Concord CCD-2248-2). Fever (Track 5), with Natalie Cole, was recorded just prior to the passing of Ray Charles. There is nothing particularly smooth about Ray's voice at this point in his life, and the track provides a wonderful counterpoint to the ethereal quality of Ms. Cole. Think of is as sandpaper vs. butter. The updatemydynaco mod effortlessly captures the essence of this contrast of vocal age, style and timbre...In the final analysis- any piece of equipment should at best never call attention to itself, but in an unobtrusive way draw you into the music. Does the updated ST-120 accomplish such a rare feat? In a word, yes..."
Chuck from New York:
"...I put both of the new boards together yesterday, and enjoyed it very much - the boards are really nicely done, and stuffing them is quite simple the way it's laid out. Hard to make a mistake..."
Rick, who has updated two Stereo 120's, says:
"You have a very nice product. The assembly instructions are excellent. Building the kit was easy. Take your time. Follow the instructions. Read them again if you don't understand the first time. The information one needs is there. Your timely answers to my emails were very helpful. The finished amplifier is better than the original. It was a fun project."
Bill from Florida:
"...What an easy kit to put together. Your manual is perfect! I have done a ton of kits in my life and this one was the easiest I
have done in awhile. I may end up getting the power supply retrofit in the future, but, so far, everything is running fine and cool.
No hums, hissing, buzzing.....nothing but music!!
Thanks again for your help and advice.
"It started when I discovered that one channel of my Dynaco audio system was
inoperative. Seeking a solution, I came upon Dan's web site via a Google
search of “dynaco". After disassembling the stereo 120 amplifier, and many
emails to and from Dan, I (we) discovered that several components in the
power supply had failed, resulting in 96 vdc frying one of the audio boards.
Dan's super heat sink, updated board seemed the ideal solution for me, a
diy-er and hobbyist, especially since I had assembled the amplifier, PAT~4
pre-amp and FM-3 tuner from kits back in 1968.
The materials included in Dan's kit are first class; the board is of excellent
quality and design, with plated-through holes for components, and the silk
screen circuit and component diagram is sharp and clear. With Dan's excellent
instruction manual guiding every step, it's very difficult for ANYONE to make
a mistake. The cost at $109.00, including shipping, for the super heat sink
version is more than reasonable - at $89.00 for the non-super heat sink kit,
it's a steal, especially compared to other rebuild offerings on EBay.
Finally, the quality of the sound coming from my “new” audio system is superb-
I think it's better than the original."
"...Thank you for making this kit available. I have already built the kits and installed them... I love this old amp again!"
"I took the new "Dynaco-Akitika Stereo 120" for a "road test" yesterday - played Saint-Saens Organ Symphony (CD) at about max listening volume for about 40 minutes - the house shook, wall hangings were vibrating, but the amp didn't even work hard. It got a bit warm around the heat sinks, but not so warm that I couldn't keep my fingers on it. Amazing......just thought you'd like to know this. Bravo!"
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