Thanks @mesch, I’ll be keeping an eye out for a 2nd smaller form factor stereo tube amp I can rotate in while leaving my pimary QS Mono 120s in place, saving these.
Contemplating with some reservations about selling off a good chunk of my vintage NOS tubes and my Pass/Forte’ Class A SS amp and preamp system I had Jon Soderberg upgrade for me. He’s 10m from me. Can’t seem to get myself to list it all.
This would help fund a nice EL34 amp I could rotate in so I can save the QS monos for a long time - they are extra amazing with the specific mundorf coupling cap, nichicon power cap, tube upgrades. Amp2 forthcoming. Will take a closer look.
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@decooney My Transcend is an earlier model which I bought used. His later version has similar circuit topology with higher grade parts. Aric can build/modify to ones desire. A fine person and easy to work with. You will enjoy your conversation with him.
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@danager I have a lower model STL hybrid that uses KT150 tubes, and I agree with your assessment, I'm using mine with apogee duetta 2 speakers and the bass is great. The hybrid amp doesn't have the power of my Krell amp, but the bass is more detailed and the midrange is better.
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@danager thx those STL amps with OTL design look fun and intersting. That Dr D guy on YT is quite giddy about Alans creations it seems.
@mesch looks like you are set, literally, no pun intended LOL. I think id like that Transcend amp you have more than my prior Inspire Hot Rod.Will look it up.
@atmasphere Ypur kind response helps me, alot. Thank Ypu for your time explaining and writing that up. It is similar with "bandwidth" discussion I had with Luke Manley at VTL. Maybe I should appreciate what i have right now even more.
Back to listening. Happy Holidays to all of you.
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This causes me pause as my 93db/6ohm speakers might be on the edge.
@decooney You are correct. In most rooms with speakers of that efficiency you’ll want more like 50 to 100 Watts. SETs, if zero feedback (and most are), have only about 20-25% usable power. Above that level, higher ordered harmonics show up on transients (where the music power is) and so causes the amp to sound ’dynamic’ since the ear uses higher ordered harmonics to tell how loud sounds are.
This is why so many people comment about the 'dynamics' of SETs. Its really distortion masquerading as 'dynamics'.
So if you are going to be successful with an SET, it really needs to be used on a speaker that is efficient enough that the amp never makes more power than that.
The other problem SETs have is making bandwidth. Typically about 7-8 Watts is the most power you can get out of an SET design before the bandwidth becomes limited. Because most SETs are used on higher efficiency loudspeakers (like horns) they often will compromise the bass response to get the highs right.
An additional problem limiting bass is an engineering problem; to operate correctly the power tube has to be placed in its most linear region of class A. There is something called a ’load line’ which helps the designer design the circuit that does that. The problem is most output transformers lack the inductance needed for them to make bass properly. This results in an elliptical load line at low frequencies- if you go low enough, its almost like the tube is driving a short, which can be very hard on it!
So for best operation, the SET really should not be exposed to low bass frequencies.
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@decooney I never did purchase the LM845. Stayed with separates. I purchased a Pass XA25 and shortly after an Aric Audio Transcend PP tube amplifier which I rotate in use with my Aric Audio 6SN7 based tube preamp.
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@decooney
I have corner horns so I can use just about anything. Saying that I just went from a 2 watt Decware to a 50 watt 845 OTL hybrid by Space Tech Labs amp and all I can say is wow. Al makes a higher watt version version but I didn't need it. I'm saving my money for his super rectifier that improves both depth and air. This amp is like a holographic generator with BASS!
I was actually looking for a 300B amp but he played this amp first and there was no comparison
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Resurrecting this 4yr old thread about 845 based tube amps. I am considering commissioning a custom build for 845 SET monos. On the fence reading posts now on the pros & cons across a few different forums.
@mesch did you ever try 845 based tube amps in your system?
@jjss49 mentioned above trying and reselling Cary 805s not quite able to drive his Proacs how he wanted. This causes me pause as my 93db/6ohm speakers might be on the edge.
I previously tried 10w triode and 50w parallel strapped pentode tube amps that worked fairly well, yet did not compare in response to my existing Quicksilver UL monos designed specifically running KT120s, KT150s.
A local audio colleague told me true 50w triode monos with big iron transformers are different beast. Ive not tried 845 Triode monoblocks yet w/my speakers yet.
Ask:
Wondering if anyone here has been through true 845 triode monos and then went back to something like KT120 / KT150 monos instead. No SS amp replies please, already got that covered, hope to hear from 845 TUBE based amp aficionados. Thx
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Ha, yeah... always expensive over there. |
@cal3713 Thanks for the thread. Just now followed it. Most of the 845s mentioned are above my budget. Need to pay off my house first. |
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Alexus Audio made in Brooklyn NY |
Thanks jdal, I will look into Alexus. |
Alexus Audio made in Brooklyn NY |
The 845 Turbo made by Coincident Technology was discontinued several years ago.
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@goldprintaudio Done. Thanks! |
Feel free to send me a PM on here or email and we can chat about who does the service work/etc. |
Thanks all. I should mention that my budget does not exceed $5000.
@goldprintaudio thanks for chiming in. I had you on my list as a dealer to call regarding my questions concerning LM amplifiers. I will do so.
At the moment I am in a quandary as to going to an integrated vs. looking for a tube amplifier to rotate with a SS amplifier using my Aric Audio tube preamp.
From my observations the Tone Import web site doesn't supply much info regarding LM. I had planned on calling them to find out more regarding the service facility they use. |
Are you looking for an amp or integrated amp? Cary Audio makes an 845 based amp -- https://www.caryaudio.com/products/cad-805rs/And Line Magnetic makes both 845 integrateds (845ia and 845Premium), and amps (503PA and 513PA). I'm a dealer for both lines. And we generally do not see issues with Line Magnetic. But if you do, there's a service facility for everything that Tone Imports brings in here in the US for repair. |
From the reviews I read, it sounds almost as good as an Audio Research 6550 amp. They are made in the USA I think...
Cheers! |
Coincident Technology makes a limited edition 845 amplifier. They’re a Toronto company. I think very highly of their Frankenstein momblocks, which are 300B. Those guys know their tubes. |
i remember my cary 805’s... massive, lovely amps with such a warm luscious sound! couldn’t drive my proacs at the time on more dynamic music in a large listening room at the time, was sorry to see them go |
I dont think that Kara (DeHavilland) is still active in this market. Perhaps I am wrong but I think this is worth mentioning.
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Cary 805 mono block amps can use either an 845 or 211 tube. |
Thanks all for the quick response. I will check out these products and call Tone Imports. |
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Art Audio is a UK based company that does 845 SETs and they have three approved service centers in the US. One in CT, MI and CA for regional convenience. That being said, I am 100% certain Line Magnetic has an approved service center in the US. I don't know who it is, but it is not possible that they don't have one.
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I've had a Line Magnetic 518IA 845 SET , which is now called 845IA, for 5 years no operating issues whatsoever. If you haven't already, you might reach out to US importer Jonathan Halpern - Tone Imports to ask if there is US based tech support ; I don't recall if there is. His email is
shindo.usa@mac.com
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