SS rectifiers - yes, big 1st cap. - no! The last thing needed is a turn on surge and/or overheating causing damage. Use a modest sized 1st cap. and a decent choke, instead of the POS C354. The reservoir position is where to pile the energy storage up. Don't forget the CL-90 inrush limiter between the rectifying diodes and the PSU filter.
I disagree - going from 30uf to 60uf is not a "big" increase or detrimental to the amplifier.
60uf is even within spec for an 5ar4.
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Some years ago I had Magnepan 1,6 and I have experimented with Dynaco
ST 70, original Quad II, E.A.R. 509 and Golden Tube Audio ST 100.
The best results in control and musicality I achieved with ST 100( a very , very good amp, if you can get a decent unit) In short you need a powerful amp to play and control the Magnepan.
ST 70, original Quad II, E.A.R. 509 and Golden Tube Audio ST 100.
The best results in control and musicality I achieved with ST 100( a very , very good amp, if you can get a decent unit) In short you need a powerful amp to play and control the Magnepan.
Reducing the value of the 1st cap. in the CLC filter allows the old and not so great power trafo to run cooler and a few more mA. of B+ be squeezed out. Increasing the conduction angle decreases the I2R heating in the rectifier winding, which makes a bit more of the AC RMS current available as B+. Whatever negative effects a smallish 1st cap. may induce are more than compensated for by the installation of a decent choke to replace the POS C354.
Reserves of current make for better bass and transient performance.
Thank you for the responses, my head is spinning. I think I am going to stick with the 12AU7, 12AX7, KT88 set up as I have all the valves on hand and will use this amp as a test mule and experiment with other tubes after the amp is complete. My intent is to use the Mark 3 frame as the audio base and a separate lower frame for the power supply. I intend to use a SS bridge with a choke input power supply. PS: I had to pull the trigger so I ordered two Edcor CXPP100-MS-5K100W, transformers. I hope this will give me a good starting point and at $200 for two it will not be a total loss.
I have used 60uf off a GZ34 and I used up to a 100uf of a 5u4..A lot of it depends on the voltage but Eli is not using the GZ34 in this case but is using Schottkys and the smaller charging cap allows you to have a larger conduction angle and that way you can pull more current from the power trafo..Remember when the charging current goes up the conduction angle gets smaller and you need that extra current especially with a power transformer that is a but inferior as far as size.
To get any dynamic range, tubes are not a good idea unless you have 120wpc, and transformers designed for a panel. ARC, Music Reference work, many do not. I have owned, 1.6, 1.7, 3.6 and tubes were not the best choice. Get a Bryston, Pass, Rotel, etc with 200wpc. This will make them stand up and bark. I had my 1.6 measured and it sucked all 90wpc from my tube amp, but the clip is so soft, it can be missed very easily. Avoid stressing the tubes, and go SS, or a more efficent speaker. There is a reason Maggiedemos with Bryston or Pass.... Jallen78
Hi Jeff!
Do you have Maggies now? I would like to try my Pyramid amp prototype with them.
Maggies
No maggies now. I have a fondness for tubes and horns, so JBL 1400 Synthesis Array, and Quicksilver M135 or a custom 70wpc amp built by an engineer from the recording industry. VCAPS throughout, and plasma tweeters with the JBL.
I miss the maggies, but my room is too small for them. No need for a sub with the JBL which tonslly share a lot with maggies...fast, articulate, and musical.
No maggies now. I have a fondness for tubes and horns, so JBL 1400 Synthesis Array, and Quicksilver M135 or a custom 70wpc amp built by an engineer from the recording industry. VCAPS throughout, and plasma tweeters with the JBL.
I miss the maggies, but my room is too small for them. No need for a sub with the JBL which tonslly share a lot with maggies...fast, articulate, and musical.
No. There are a couple on Craigslist which would be a good opportunity to audition with your amp. Jeff
os. Noticed you are in Pleasant Hill. I am in Danville...
os. Noticed you are in Pleasant Hill. I am in Danville...
I remember trying out a pair of Magnepans with my audio buddies somewhere in the late 90's. No idea which model, sorry.
It was driven by some heavy ss amp and its power meters were dancing around the 100W mark.
Being valve fanatics, we were more than hesitant to see how badly hollow state would hold up (or not) to this demonstration of power.
The valve amps sounded pretty good actually.
And guess what: it sounded louder as well... WTF?
These were PSE 300B mono's rated at a measly 25W.
What made them special were the ridiculously oversized transformers. I think each mono was at least as heavy as the ss stereo.
It was driven by some heavy ss amp and its power meters were dancing around the 100W mark.
Being valve fanatics, we were more than hesitant to see how badly hollow state would hold up (or not) to this demonstration of power.
The valve amps sounded pretty good actually.
And guess what: it sounded louder as well... WTF?
These were PSE 300B mono's rated at a measly 25W.
What made them special were the ridiculously oversized transformers. I think each mono was at least as heavy as the ss stereo.
The problem with tubes is they compress when pushed. If they are measured for output into a panel, they are pushed to the ragged edge, unless in a small room, wood floors, low ceiling, and non demanding music. I tried 4- 90wpc tube smps, with electronic eq, and with organ music, they tapped out at modest listening levels. Transistors are just a better fit. They sound better with more output. They don't compress. Tubes usually compress to 50 Hz to 15khz, and distortion rises. Tubes distort softly so they may be nearing oscillation, with no warning. My 3.6 sounded best with a Bryston 14BSST on the bass, 4bst on top with Marchand xm44. About 1000wpc...Very effortless...
Bryston amps have good PSUs, with plenty of current reserves. Try a tube amp, like a "McShaned" H/K Cit. 2, that also has a PSU with cojones and you may change your mind.
While definitely power hungry, "Maggies" present a tube "friendly" load of 4 ohms that varies very little.
BTW, I can tell you from personal experience that a H/K Cit. 2 refurbished ala McShane bests quite a few SS amps at their own game of bass performance.
While definitely power hungry, "Maggies" present a tube "friendly" load of 4 ohms that varies very little.
BTW, I can tell you from personal experience that a H/K Cit. 2 refurbished ala McShane bests quite a few SS amps at their own game of bass performance.
Maggies are friendly at 1khz, and are less friendly as the notes get lower. At 50hz, very nasty power needs. I have a 70wpc tube amp, likely better than the refurbished Citations, and it still failed when we ran low frequencies into the maggies. It is not designed for Maggies however with primary and secondary windings for dynamic speakers. It makes a true 70wpc into 20hz, thus the move to horns. It has VCaps, silver wire, hand wound transformers, military parts, matching of everything. Flat from 5hz to 100k, and got me banned from bringing it to some audio stores.
With most tubes , Maggies lack dynamic range....unless there are Carver Cherry 180. They work fine. I drove the 1.6 fine with 70wpc, or 90 wpc tubes, not the 3.6.
With most tubes , Maggies lack dynamic range....unless there are Carver Cherry 180. They work fine. I drove the 1.6 fine with 70wpc, or 90 wpc tubes, not the 3.6.
Here is the review from one guy who bought one of previous prototypes of my Pyramid:
My favorite component is my Wavebourn Pyramid VII, Prototype 1, built to my specs and as far as I know, the only one in existence. I originally bought the Pyramid V, also a prototype that was damaged during shipping (as seen below). I always wanted to try a tube amp but I've got some terribly inefficient Magnepans and the tube power needed to drive them was just too cost prohibitive. After searching for months I rolled the dice on the Wavebourn and it's been the best stereo purchase I ever made. The designer, a Russian dude from Cali, was basically going to lose his home unless he raised some quick cash...so I got this amp for less than the cost of the power supplies. The V was originally designed to be used in a PA system and as a guitar amp. After seeing it on Audiogon I researched Anatoily, the designer, and what little I could find out about him he seemed very well respected among his peers. When the V showed up the power supplies were literally ripped from the chassis so, to make a long story short, it took six months but he tweaked the circuitry and I ended up with the Pyramid VII. I've had Acurus, Rotel and some other lesser SS amps in this system and the Wavebourn is by far the best sounding. Very, as they say, musical...and not fatiguing at all. The truth is that I bought this amp because I liked the way it looked. I love it for how it sounds and I'll never part with it because of the history I have with it and the uniqueness/cool factor. At 80W X 2 it drives the Maggies but not quite as loudly as I like when cranking NIN, Rob Zombie, etc. For classical, jazz and blues though...
My favorite component is my Wavebourn Pyramid VII, Prototype 1, built to my specs and as far as I know, the only one in existence. I originally bought the Pyramid V, also a prototype that was damaged during shipping (as seen below). I always wanted to try a tube amp but I've got some terribly inefficient Magnepans and the tube power needed to drive them was just too cost prohibitive. After searching for months I rolled the dice on the Wavebourn and it's been the best stereo purchase I ever made. The designer, a Russian dude from Cali, was basically going to lose his home unless he raised some quick cash...so I got this amp for less than the cost of the power supplies. The V was originally designed to be used in a PA system and as a guitar amp. After seeing it on Audiogon I researched Anatoily, the designer, and what little I could find out about him he seemed very well respected among his peers. When the V showed up the power supplies were literally ripped from the chassis so, to make a long story short, it took six months but he tweaked the circuitry and I ended up with the Pyramid VII. I've had Acurus, Rotel and some other lesser SS amps in this system and the Wavebourn is by far the best sounding. Very, as they say, musical...and not fatiguing at all. The truth is that I bought this amp because I liked the way it looked. I love it for how it sounds and I'll never part with it because of the history I have with it and the uniqueness/cool factor. At 80W X 2 it drives the Maggies but not quite as loudly as I like when cranking NIN, Rob Zombie, etc. For classical, jazz and blues though...
Yes...Have you ever noticed that everyone that like Quads also likes horns and maggies..I have Martin Logan CLXs and I also have a pair of Newform Research 645s but I also have angel horns from Anyd Vanderkruk with various JBL and Altec compression drivers.
Once one is accustomed to the more seamless sounds, it is hard to go back to a box sound. Jallen78
On the new GZ34s like the Sovteks,it can be an issue but on the old Mullards and probably new Mullards, 60uf may not be an issue..Eli likes to play it safe but the idea of using a smaller charging cap off the rectifier gives you a larger conduction angle and this allows you pull more current from the power transformer if you get more exotic with the power supply build down stream.
I never use lytics of a GZ34 anymore because a poly film even at 30uf is much more efficient as far as energy delivery...If you have an integrated amp with a gz34,putting a 35uf poly off the rectifier gives amazing results.
Check out the Sherwood S5000 I did and you can see 35uf@500v poly on the left that goes to the gz34..I stuck it in the cap hole that held the original 50v quad can.
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Just saw this thread...I have Magneplanar 1.6s as well. Have owned them for years. I drive them two ways, older restored bipolar transistor amps that are 200 Watts / channel and various restored Dynaco ST-70s. I have other amps as well.
I found that if I biamp the 1.6s with one ST-70 per speaker, it can manage it well enough for almost loud levels. I have used a pair of Bob Latino M125s with KT120s. That did very well with the 1.6s. I measured the power output of the M125s on my bench and at 1% distortion they were 128 Watts.
As mentioned before, Magneplanars need power. But, if you are not playing super loud and looking for deep bass, I found lower Watts to be ok.
I enjoy trying different amps with these speakers. I have found combinations I like over the years. Enjoy.
I found that if I biamp the 1.6s with one ST-70 per speaker, it can manage it well enough for almost loud levels. I have used a pair of Bob Latino M125s with KT120s. That did very well with the 1.6s. I measured the power output of the M125s on my bench and at 1% distortion they were 128 Watts.
As mentioned before, Magneplanars need power. But, if you are not playing super loud and looking for deep bass, I found lower Watts to be ok.
I enjoy trying different amps with these speakers. I have found combinations I like over the years. Enjoy.
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