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Hey-Hey!!!, I got my old CItation II up and running after completing a PS rebuild. I also replaced all the old carbon comp resistors when I got into it and replaced all the capacitors. The original WW resistors stayed. It sounds good, and is not lacking in power. The meter is not serviceable, so I am going to put in a jack and keep the switch provided by H-K. The old dual bias pots also left, replaced by sealed individuals of 10k each. My first impression is that this amp is something special. More time listening will be needed, but that's a job I can do. cheers, Douglas
A good friend uses the Citation 1 and 11 combo. The pre-amp really is something unique but what is of interest is we use both the 11 and the 1v. The four is a little simpler circuit but I tend to like the sound a little better; however the 11's have more power and really sock home the fundamentals. Nice hefty transformers. Have you read in AudioeXpress Norman Thagarrds article where he bridges either six or eight of these amps on each channel for a total of 600 watt output? He tells of having to brace the floor joists to support the weight of the whole group.
The aX with that had that article had the last issue of my trial subscription intended to capture Peter Millett's SE E-Linear article. I keep seeing conflicting limits published on how powerful a *really good* tube amp can be. Of course some say a 3W 2A3 is te end....but I think it is a bit higher than that! cheers, Douglas
how powerful a *really good* tube amp can be
Well, that is a loaded question. To best answer I would say you have to divide it up into commerical amps and DIY amps. Unless you get into real high voltages high power amps basically require feedback because of the need to use pentodes. Doing feedback right isn't so easy and the average DIY type lacks the experience and equipment to do a top notch job. I doubt you or I would ever dream up the citation schematic now would we? So for DIY stuff I might set a limit at around 30 watts and ideally more like 10 so we don't have to leave class A operation. Now when you get into the commercial area all bets are off. Have you ever looked at the Wolcott white papers? Interesting reading. I always wanted to hear one of the electronluv amps too. But yes, the citation is a special amp the likes of which I doubt will ever be reproduced again. Russ
Re: how powerful a *really good* tube amp can be
Hey-Hey!!!, I got this beastie to eval its output Iron. If one wants power and maintain Class A operation there is only one way: high idle dissipation. The 813 plate curves in U-L look quite good for the Cit.II's output Iron. Same for the Heath W6 with its comparable Peerless 16431. Either way, more power is an interesting experiment. There must be some limit to the output Iron parasitics making too much trouble as power/size goes up. I am certain the Duece's Freed OP's will be fine. Slightly more idle bias and voltage but not much. 650V and 150 mA should be about right....:) In the meantime, it is nice to have a second amp so I can play with the primary. cheers, Douglas
Hi All, Norm (and Doug) got kits (and other parts in Norm's case) from me to redo their Citation IIs. BTW, Norm and I correspond all the time, he has a couple "spare" Cit II amps besides his 8 amp setup. The 8 amps produce 480 watts per channel with peaks of over 800 watts/side. It really is a special amp after the kit(s) installation. According to the guys who borrowed one from us to use last week in Vegas it was the best amp on the premises. You'd be amazed at the number of well known audio gear designers who are closet Citation freaks! On the Cit IV - if you don't use tone controls and are using the line stage you have a simple 1 tube per channel line amp. One 12AX7 per channel is all that's active. The IV can be improved a lot with power supply upgrades (as can the Cit I), it's a b*tch to work on though. If you'd like to see some pics or get an idea how far into the Citation tube gear I am take a look over on my site. There's even a scan of the 1961 sales brocure if you are interested - check the prices! I'll try to stop by here accasionally and if anyone has any Citation questions I'll be happy to help if I can. Thanks to Russ for turning me on to this forum. Jim McShane - Citation Amps & Tubes
After pressing 'submit' it dawned on me I had not mentioned the source of my parts kit. Jim did some trading for some valves I had, and I got his full-on resto kit and directions. They made a complicated looking job relatively simple. I'll make a few suggestions: remind the rebuilders that both sides are the same, and take one side apart at a time. That way, there is the original( hopefully) on the other side to compare to. I still managed to neglect the g2 connection on the 'B' side pair of 12BY7's. Low voltage power up with a variac put that one to the light. All the bits, and all the wire to do the job came with the kit. The new PS is dual mono, broken up into two branches after the main B+ to the finals. I replaced the 9-pins with old nearly NOS from a 'scope. Thank goodness nobody rolls tubes in scopes. The initial testing pre-resto indicated the originals were a bit dodgy. My carbon comp resistors had also drifted significantly, so they got replaced with a mix of carbon film( mostly 2W types from Handmade Elec) and metal film IRC GS3. Matched pairs of Tektronix 12BY7 were a nice fine in my college surplus and salvage...:). And to a previous poster, Jim is also one of the good sources for tubes. Anyway, I am happy with the amp, and having confirmed the quality of its output Iron, feel quite confident on borrowing its Iron for the 813 project. It'll be neat to see how it stacks up against the Heath W6's Peerless Iron. cheers, Douglas
Hi Doug! Thanks for the email too. To fill in everyone about the email subject, Doug has a feeling he'd like to use a couple different types of coupling caps than I supply in the 2-A cap kit (not the power supply). I told him he must be nuts (just kidding!)... no, I really told him that he's the only person who ever mentioned that, but of course Doug has a different viwepoint than most Citation II owners! Obviously he should feel free to try any cap he wants, but one thing is certain - space is limited! Be aware that with about 32db of NFB, the Citation II is less likely to demonstrate big sonic differences between types of caps, resistors, etc. Anyway, I sure do appreciate the kind words Douglas - THANKS a lot!
Hey Jim; I have done business with you regarding my old Cit 1. The nicest sounding phono stage I ever heard. It is a pleasure to see you here. Your site is highly recommended.
Hey-Hey!!!, Actually, the place I'd really like to try a cap is the common g2-common cathode nodes of the PP driver circuit. However, I am sure there is a reason for the design, and when I have developed understanding of it, I may try something. On the space, I do wish there were more of it. I did keep the original wire dress as well as all the values. The nice thing with this amp v. its primary contemporary competition the McIntosh, all the feedback is negative. No silly bootstrapping or orher such nonsense. I had a gathering at my place today, and the Deuce did not get rotated in. Lots of other cool stuff did, can't go hogging all the play time, no? I got plenty of 'nice job!'s when I showed them the underside; that is one impressive amp, and I am glad I took the time to own one. cheers, Douglas
Come on out to the Great Plains Audiofest in May. There is no exhibitor's fee, just a bunch of the best folks in audio. I'd love to see you there.
Jim, you mentioned the line stage of the IV. I poked around your site to see if I could find a schematic, but did not. Do you have a schematic you could share?
Hi Steve, I have the H-K, I need to scan it and upload it. Give me a couple days, I'm really busy!
The Cit IV power supply is up on my Resources page, the other should be up later today.