That might be a good question if I was rational😀
So far on my audio journey I have rebuilt a PAS 3 with the best of parts from Tubes4hifi, the Cornet, and then upgraded the Cornet. I also have a McIntosh C2300 that I use as a reference to gauge what I build.
Since my soon to be installed Koetsu is a MC cart, I would need to build a step up transormer to use the Cornet. Which leads me to the current quest of the ultimate phono stage!
But the main reason of course, is I like to build stuff! I could just be satisfied and use the McIntosh, but I didnt build it!
OK, I just wanted to establish that you were crazy. Now I can talk.
I've built Bench's LRnoC circuit twice. It's pretty good and if you're out for discovery rather than a turnkey shuffle you might find it worth doing , though it might be pricy to do it with inductors worth using. My only justification for building it was that I already had the transformers and I just decommissioned one thing to build another. It was a distinctly different sound and you'll hear it the second you fire it up.
The ones I built measured reasonably well as I recall (with reverse RIAA circuit at input) but I've since built other circuits I like better. I never built the LRC circuits as for me the only reason to use L was to see what would happen if we got rid of C.
Bench's LRnoC circuit will call your attention to building details and design for ease of adjustment as with the positive feedback it can oscillate easily on power up and down until properly set up. At the time I wondered if that might have been the reason the original shown at ETF had a mute circuit, I don't know. But once set up it's a very nice sounding rig and if you're looking to explore it's probably something you'll just have to do, wild man - Anyway, thems my first thoughts.
ok, one other thing, What were the upgrades to the Cornet?
I've built Bench's LRnoC circuit twice. It's pretty good and if you're out for discovery rather than a turnkey shuffle you might find it worth doing , though it might be pricy to do it with inductors worth using. My only justification for building it was that I already had the transformers and I just decommissioned one thing to build another. It was a distinctly different sound and you'll hear it the second you fire it up.
The ones I built measured reasonably well as I recall (with reverse RIAA circuit at input) but I've since built other circuits I like better. I never built the LRC circuits as for me the only reason to use L was to see what would happen if we got rid of C.
Bench's LRnoC circuit will call your attention to building details and design for ease of adjustment as with the positive feedback it can oscillate easily on power up and down until properly set up. At the time I wondered if that might have been the reason the original shown at ETF had a mute circuit, I don't know. But once set up it's a very nice sounding rig and if you're looking to explore it's probably something you'll just have to do, wild man - Anyway, thems my first thoughts.
ok, one other thing, What were the upgrades to the Cornet?
I have also heard of a couple issues on the Bench design. The oscillation like you mentioned and low bass. Although no reports if the issues were overcome and/or how. There is no doubt that quality of parts, layout and build detail must be top notch. But somehow some commercial units and Thomas's LCR have found a way to overcome.
On the Cornet, the usual upgrades, nude resistors, Mundorf Silver/oil caps, Russian caps, Dynacaps.
This is a pic from one stage of playing around;
On the Cornet, the usual upgrades, nude resistors, Mundorf Silver/oil caps, Russian caps, Dynacaps.
This is a pic from one stage of playing around;
I don't dream of building "the perfect phono stage" as I don't believe such a thing exists, budget or no budget. All circuits are a compromise, but some are more compromised than others. People who insist on starting from a poor choice (e.g. those who insist on DC coupling for valves, those who insist on using inductors where capacitors would do a better job, those who insist that the circuit must be complicated and expensive, those who insist that the circuit must be simple) are likely to face bigger problems.Coasttocoast said:
IMO, good design will get you improved performance much more effectively that "glamor" names and questionable "upgrades." I have two phono stages in house at the moment which push the SOTA for tube preamp performance, neither of which has anything in it (other than the tubes) that you can't buy from Mouser or Digikey.
I think some builders see things in terms of projects defined like, "EL84 amp" "SE 45 Amp" "PPP Amp" "Passive Pre" etc. and I imagine them saying , "I want to build an 845 amp!" for example, and they build one. They plan it all out well and build it like a finished product right from the start so once it is finished it's finished. That's it. They listen to it for a while and then something new comes on the radar and they move on. Once it's a few miles behind them they start to think like, "Yah , 845 amp, been there done that." and they feel that a return to anything with the same tube again is a step backward.
It looks to me that with this approach there's not a lot of experimentation with operating point and topological variations. If that's how it's done though then how can the builder really know what does what? It's OK I guess if they're more interested in accomplishing builds than working on understanding the circuit's workings but to me, optimization of the circuit is where it's at. It teaches more than building it in the first place. SO o o o , I have this irresistible urge to say before you pass over your Cornet as a done deal, try some more stuff. The most obvious to me is power supply. Can it be a better design? Work in a shunt regulator (Kit form of the Salas if you're in a hurry) , or . . . . heaven forbid, a series reg. My basic thing is, if you're an explorer, don't let the engineers put you off your course. If they don't want to help you explore leave them on the sidelines. (They don't all agree with each other anyway!)
On the LRnoC track, I can confirm that those problems you mentioned with the Bench design were all overcome and it sounded good. I made changes and listened for almost a year to get it where I was really satisfied that I'd covered its turf.
Look at Christian Rintelen's version on his web page. He loves his and has by all accounts (some published) a very good sounding system.
It looks to me that with this approach there's not a lot of experimentation with operating point and topological variations. If that's how it's done though then how can the builder really know what does what? It's OK I guess if they're more interested in accomplishing builds than working on understanding the circuit's workings but to me, optimization of the circuit is where it's at. It teaches more than building it in the first place. SO o o o , I have this irresistible urge to say before you pass over your Cornet as a done deal, try some more stuff. The most obvious to me is power supply. Can it be a better design? Work in a shunt regulator (Kit form of the Salas if you're in a hurry) , or . . . . heaven forbid, a series reg. My basic thing is, if you're an explorer, don't let the engineers put you off your course. If they don't want to help you explore leave them on the sidelines. (They don't all agree with each other anyway!)
On the LRnoC track, I can confirm that those problems you mentioned with the Bench design were all overcome and it sounded good. I made changes and listened for almost a year to get it where I was really satisfied that I'd covered its turf.
Look at Christian Rintelen's version on his web page. He loves his and has by all accounts (some published) a very good sounding system.
I remember seeing and hearing an inductor based phono preamp back in the 1980s. It certainly had a different sound to it. IIRC, the big problem with it was its low impedance to keep the inductors values reasonable. I don't remember what the gain stage was, haven't been able to find a schematic or photo.
Seems it was one of those "This is a fun a different idea" that turned out well enough.
Kind of pain, tho.
Seems it was one of those "This is a fun a different idea" that turned out well enough.
Kind of pain, tho.
Amen! Just like people who "upgrade" their speaker crossovers by replacing the original "crappy" capacitors with super low ESR audiophile types, and then bask in the improved resolution, better clarity, tighter image focus, etc. when what they have actually done is altered the amplitude response in the crossover region! Measure everyone, measure...before and after so-called improvements.
I appreciate your reply, sorry for the late reply. Been preoccupied with my SST-70 monoblock project.
I spent over a year playing around with the clarinet and coronet 2. No issues and I'm not just passing them by either. But my cart is MC now and I didn't want to jump in and purchase step up transformers as I now have this McIntosh C2300.
Thanks everyone for all the comments, both positive and negative. I enjoy the research, planning, and execution of building "stuff". From amps to cars to homes to $100m retail stores (real work). I'm on an audio journey and trying to learn as much as I can in the process.
Since I have added this McIntosh C2300 into my system I have come to appreciate the convience of its remote control. It's a $6k piece of gear, not reference quality, but not a slouch either. So I've decided to start experimenting on it first. First up will be to upgrade the capacitors in the MC phono section and pre section. Surely some improvement to be had to replace the $2 wima caps with some Cardas and Mundorf silver/oil and silver/gold/oil caps. I'll start another thread for those discussions.
I haven't given up on a LCR phono stage, still in the planning stage for now. I have some professionals getting some info for me that I'm waiting on. But not as much of a priority as I'm enjoying my SP-10 through the C2300. Just hit 99db spinning some Daft Punk!
Last edited:
I took this thread for a question.
I am working with a complex LCR phono with 5 irons /channel original Tango + EC8020 TFK.
Lot of tests and measurement with two Audio Precision and the results are good.
What I see that on hundreds of threads around the web that nontest lab were published
Lot of simulation !!
Someone can help me to find some real test?
Just to compare and, in case, speak on
Walter
I am working with a complex LCR phono with 5 irons /channel original Tango + EC8020 TFK.
Lot of tests and measurement with two Audio Precision and the results are good.
What I see that on hundreds of threads around the web that nontest lab were published
Lot of simulation !!
Someone can help me to find some real test?
Just to compare and, in case, speak on
Walter
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.