Citation V - Questions from a beginner
jdarg
It has been sitting idle for roughly 20 years, and I am interested in
restoring it. This is my first vintage tube amp, so I have some questions
that maybe some kind people can answer for me.
1. How does the stock Citation V compare to a stock Dynaco ST-70 or any of
the vintage McIntosh models, which seem to be pretty popular amps? My
understanding is that the HK is of a better component and overall sound
quality (at least stock) and higher bandwidth than the ST-70, but probably
not nearly as good as any of the vintage McIntosh tube gear, correct? What
is the hi-fi blue book value of the Citation V in varying conditions?
2. I don't own a variac - should this be the next thing I buy? Should I not
even power it up initially w/out one? The amp supposedly worked when it was
put into storage, but has not been tested since.
3. I understand that the first step in restoration would be to isolate and
replace the components which are out of spec, esp. the caps and resistors.
Are there any good sources of these NOS parts, esp. filter caps, which from
what I've read has given me the impression they are impossible to find now?
Will I hear a big difference if I overhaul with some of the higher-grade
newer components w/ tighter tolerances, or isn't this going to make a big
difference? I think I definately want to stay stock unless I have a lot to
gain otherwise. Are there any other "must do" mods or weaknesses that should
be addressed?
4. What is the proper method to test the transformers? I've seen multimeters
in a catalog (either Digikey or Mouser) which claim they can test trannies -
is there a simpler way?
5. I think I want to stay w/ the stock 7581's, but is there another tube
which is better suited and can be relatively easily substituted w/out a lot
of hassle? From what I've read 7581's are good (but not excellent) tubes,
but are harder to come by. What about the other tubes?
6. I am waiting for the Sam's Photofacts for this amp, and its the only
documentation I will have to start with. Is there any other literature
related to the Citation V I should get? Any good books for restoring vintage
hi-fi? I'm not completely new to basic electronics, but I'm far from being
an electrical engineer.
7. Are there any generous Citation V owners out there willing to be a mentor
of sorts and answer my questions which arise throughout this project? I
promise I won't hassle you too much!
Thanks.
Gene E. McCluney
>
> 5. I think I want to stay w/ the stock 7581's, but is there another tube
> which is better suited and can be relatively easily substituted w/out a lot
> of hassle? From what I've read 7581's are good (but not excellent) tubes,
> but are harder to come by. What about the other tubes?
>
>
KT-66 available from Ned Carlson, or you chould (chuckle) use the Western
Electric 350b (only available used or NOS) if available at all.
These would be the most closely matched to the USA 7581/KT-66 that came
stock with the amp. Perhaps a 6L6GC might also work, if one was careful
with bias.
The 7581's are still available as military surplus from some vendors.
Gene McCluney
--
Gene E. McCluney
mccl...@earthlink.net
Sheldon D. Stokes
I'd stay away from the chinese tubes unless you like fire shooting from
your amp.
Sheldon
--
"...from Genghis Kahn to the Fuller brush man, they're just a bunch
of losers like me" -Dave VanRonk
Remove SPAM_BE_GONE from my address to reply to me.
Sheldon D. Stokes
<ruh...@prodigy.net> wrote:
> 1. How does the stock Citation V compare to a stock Dynaco ST-70 or any of
> the vintage McIntosh models, which seem to be pretty popular amps? My
> understanding is that the HK is of a better component and overall sound
> quality (at least stock) and higher bandwidth than the ST-70, but probably
> not nearly as good as any of the vintage McIntosh tube gear, correct? What
> is the hi-fi blue book value of the Citation V in varying conditions?
I've got the big brother, the citation II. it's a much nicer amp than the
ST-70, and you'd hope so cause you could have bought a lot of ST-70's for
the price of the Cit II. However the St-70 holds up nicely against it.
Overall it's not hard to hear that the Cit II is a better amp, but the
St-70 does do some things very well. I'd be happy with either (but I have
both. :) )
Given my limited experience with mac gear, I'd rather have the Citation II
or the ST-70.
> 2. I don't own a variac - should this be the next thing I buy? Should I not
> even power it up initially w/out one? The amp supposedly worked when it was
> put into storage, but has not been tested since.
You can put a lightbulb in series with the power cord to limit current
into the amp.
A few of the amps I have, I jsut fired them up, if a part is bad, I want
it to be obvious where it is by the big black mark. Other amps I've
gotten like the Citation II (which I knew was a winner), I rebuilt the
entire thing before I fired it up.
> 3. I understand that the first step in restoration would be to isolate and
> replace the components which are out of spec, esp. the caps and resistors.
> Are there any good sources of these NOS parts, esp. filter caps, which from
> what I've read has given me the impression they are impossible to find now?
> Will I hear a big difference if I overhaul with some of the higher-grade
> newer components w/ tighter tolerances, or isn't this going to make a big
> difference? I think I definately want to stay stock unless I have a lot to
> gain otherwise. Are there any other "must do" mods or weaknesses that should
> be addressed?
Filter caps in the big cans (twist-lok) can be had at antique electronics
(www.tubesandmore.com) or from Ned at triode electronics
(www.triodeel.com). The folks who make them jsut came out with a 525 volt
line of cans, so you will have no problem. I rebuilt my cans rather than
paying $25 each for the 5 cans under the Citation II. However the V is
much more simple amp and should have fewer filter cans.
You deffinatally want to rebuild the power supplies with new caps. The
bias supply is very important to keep working well.
If it were my amp, the next thing I'd do is replace the coupling caps.
Those original black cat caps are awful. Then listen to it for a while.
If you are really ambitious, replace all the resistors.
My ST-70 had a channel level imbalance until I replaced the resistors.
> 4. What is the proper method to test the transformers? I've seen multimeters
> in a catalog (either Digikey or Mouser) which claim they can test trannies -
> is there a simpler way?
There was a great post about a year or so ago on testing trannies with a
multimeter. It boiled down to measuring the resistance of each winding
and making shure there aren't any shorts between windings and between any
winding and the core. I'd bet your trannies are fine if it was working
when it was put away.
> 5. I think I want to stay w/ the stock 7581's, but is there another tube
> which is better suited and can be relatively easily substituted w/out a lot
> of hassle? From what I've read 7581's are good (but not excellent) tubes,
> but are harder to come by. What about the other tubes?
>
Svetlana 6L6GC's would be a good thing to try. They should drop right
in. The Sovtek 5881's should also drop right in. There are still a lot
of NOS 7581's out there.
> 7. Are there any generous Citation V owners out there willing to be a mentor
> of sorts and answer my questions which arise throughout this project? I
> promise I won't hassle you too much!
I haven't poked through a V, but I've done a complete rebuild on my
citation II, and I'll be glad to answer any questions you have.
macfa...@hotmail.com
stokes@SPAM_BE_GONEexis.net (Sheldon D. Stokes) wrote:
>
>
> I'd stay away from the chinese tubes unless you like fire shooting from
> your amp.
>
> Sheldon
>
> --
The truth is that the recent Chinese power tubes (specially the KT66 retro &
KT88 classic) are pretty darn good. You said the same thing a few months ago
when I posted about my (then) recently acquired quad of KT88 Classics. So far
so good and its 600 hours and counting! Needless to say, these babies have
long passed the infant mortality period. The sound is fantastic and you can't
find a better looking KT88. Times have changed Sheldon, don't cling on to the
past!
Regards,
Nestor
-----------== Posted via Deja News, The Discussion Network ==----------
http://www.dejanews.com/ Search, Read, Discuss, or Start Your Own
Jamie
jdarg wrote in message <70rlnr$d5ic$1...@newssvr04-int.news.prodigy.com>...
>I have just purchased and am waiting to receive a Harman/Kardon Citation V.
>It has been sitting idle for roughly 20 years, and I am interested in
>restoring it. This is my first vintage tube amp, so I have some questions
>that maybe some kind people can answer for me.
>
>the vintage McIntosh models, which seem to be pretty popular amps? My
>understanding is that the HK is of a better component and overall sound
>quality (at least stock) and higher bandwidth than the ST-70, but probably
>not nearly as good as any of the vintage McIntosh tube gear, correct? What
>is the hi-fi blue book value of the Citation V in varying conditions?
Bottom line (Yes I have owned both) A Citation V kicks a ST-70s ass all
over the place. Better mids, WAY better highs and lows, and just a more
transparent sound. More powerful, too. I like Mac gear, but, honestly, I
don't prefer it because I find it to be very colored (colored well,
but.....) and the HK circuits are much more neutral sounding in my
opinion...... Heck, the voltage amp section of the Citation II is
practically a front end from an oscilloscope. Mac gear is nice, but it's
like viewing the musical world through a slightly tinted window. The tint
can sure reduce glare and eye strain, but It would be nice to see all the
detail once in a while, no? I can hear Nestor flaming me already...... But
that is how I feal about mac gear. It certainly looks cooler, though.....
>
>2. I don't own a variac - should this be the next thing I buy? Should I not
>even power it up initially w/out one? The amp supposedly worked when it was
>put into storage, but has not been tested since.
>
A variac is used to lighten the load on the electrolytic caps as they slowly
re-form themselves up to the proper voltages. However, I would reccomend
wholesale replacement of ALL ELECTROLYTIC caps on your amp just to be safe.
It'll sound stiffer, too.
>3. I understand that the first step in restoration would be to isolate and
>replace the components which are out of spec, esp. the caps and resistors.
>Are there any good sources of these NOS parts, esp. filter caps, which from
>what I've read has given me the impression they are impossible to find now?
>Will I hear a big difference if I overhaul with some of the higher-grade
>newer components w/ tighter tolerances, or isn't this going to make a big
>difference? I think I definately want to stay stock unless I have a lot to
>gain otherwise. Are there any other "must do" mods or weaknesses that
should
>be addressed?
>
I decided to totally re-do the Cit V circuit in another chassis (I bought a
homebrew that had cit V trannies in it) So, I gutted the thing, went on
down to uncle Ned's and bought myself a crapload of caps an resistors. I
found that his yellow "mystery caps" and the metal film resistors work very
well in this amp. They make the tone very clean and transparent, but not
harsh or brittle (unless the CD is !!) I rebuilt every last component in
the thing, and the homebrew definately sounds better to my ears than the
original, though the original was just a little warmer.
>4. What is the proper method to test the transformers? I've seen
multimeters
>in a catalog (either Digikey or Mouser) which claim they can test
trannies -
>is there a simpler way?
I would bet that they're fine if they worked when the unit was stored.
>
>5. I think I want to stay w/ the stock 7581's, but is there another tube
>which is better suited and can be relatively easily substituted w/out a lot
>of hassle? From what I've read 7581's are good (but not excellent) tubes,
>but are harder to come by. What about the other tubes?
If you re-do the bias scheme with a circuit that will allow a wider range of
bias voltages (multi-turn pots) and modify the bias supply voltage, you can
try a WIDE range of tubes in there. So far, my favorites are the Yugo
KT-90, and the Tung-Sol 6550. BTW, if you can get a pair of Tung-Sol 6CG7s
for the drivers, you will be very glad you did. But, re-doing the bias will
give you all sorts of options. 7581,6L6,EL34,KT-90,KT-88,KT-66,6550
etc....... The only thing is that the higher power tubes pull extra current
and make the power tranny run a little hot. But, I have about 1000 hours on
a quad of KT-90s, and about 200 hours on a set of Tung-Sol 6550s, and my
tranny is still doing fine. And, that heat problem can be fixed just by
adding an additional filament transformer, either outboard or hidden inside
(probably outboard on that size of a chassis).
>
>6. I am waiting for the Sam's Photofacts for this amp, and its the only
>documentation I will have to start with. Is there any other literature
>related to the Citation V I should get? Any good books for restoring
vintage
>hi-fi? I'm not completely new to basic electronics, but I'm far from being
>an electrical engineer.
>
>7. Are there any generous Citation V owners out there willing to be a
mentor
>of sorts and answer my questions which arise throughout this project? I
>promise I won't hassle you too much!
Well, I dunno about mentor, but I'd be glad to answer anything I can. *^)
Good luck!
Jamie Campbell
Ned Carlson
(Sheldon D. Stokes) wrote:
>I'd stay away from the chinese tubes unless you like fire shooting from
>your amp.
>
>Sheldon
Doesn't seem to be the case with these new Chinese
"GEC Repro" (not to be confused with the straight
bulb version some folks are selling) KT66.
We've sold a mess of 'em (and have an OEM
customer using them), have backorders for more,
and so far *zero* failure rate in service.
(We sent back a couple for rattles)
One customer actually had 'em running in a
JTM-100 Marshall,playing them full goose bozo
at 600V of B+ biased at 60 ma per tube!
That's 36W of static disspation!
Believe me,if they sucked, we wouldn't
sell' em,or we'd be dumping them at cost
or less.
Ned Carlson Triode Electronics "where da tubes are!"
2225 W Roscoe Chicago, IL, 60618 USA
ph 773-871-7459 fax 773-871-7938
12:30 to 8 PM CT, (1830-0200 UTC) 12:30-5 Sat, Closed Wed & Sun
http://www.triodeel.com
Your Start Page for Tube and Tube Amp info on the net...
http://www.triodeel.com/tlinks.htm
Ned Carlson
McCluney) wrote:
>You could use the Groove Tubes Russian KT-66, or the new new Chinese retro
>KT-66 available from Ned Carlson, or you chould (chuckle) use the Western
>Electric 350b (only available used or NOS) if available at all.
Chuckle is right. Wish I hadn't sold my 350B's...
>
>These would be the most closely matched to the USA 7581/KT-66 that came
>stock with the amp. Perhaps a 6L6GC might also work, if one was careful
>with bias.
Good 6L6-GC are interchangeable with 7581A in that amp.
Plug 'n play in a CitV, same bias.
If one likes nice colored bases like the original US 7581A,
the Tesla & Svetlana 6L6-GC have 'em. We stock 'em both.
macfa...@hotmail.com
"Jamie" <jcc@CUT_THIS.wwa.com> wrote:
> I can hear Nestor flaming me already...... But
> that is how I feal about mac gear. It certainly looks cooler, though.....
>
>
>
Naa, my flaming days are over :-)
Seriously though, how does the Citation V compare to a Mac in actual
plate+screen dissipation? How long would those 7581s last at the correct
factory bias specification? I know the Citation II fries the tubes at 100ma
but how about the V?
Sheldon D. Stokes
> The sound is fantastic and you can't
> find a better looking KT88. Times have changed Sheldon, don't cling on to the
> past!
I'd like to think that all tubes are good and plentiful. But I have a
friend who had fire shoot from his Citation II due to chinese power
tubes. They may be better, but I've been scared off by them; I'll use
russian or yugo ones. I like the idea that there are more good tubes out
there, I hope they are.
It's the same concept for me as american cars, they sucked in the past and
they lost my business, now they have to be better than imports (not just
as good) to get my business back.
Mr. James C. Mcshane
Nominal plate voltage is 450, screen voltage is 440.
Sounds easier on the tubes than Cit II.
I'm in the process of rebuilding a Cit V now, and I plan to use some
7581As as power tubes.
Jim McShane
MLJ...@prodigy.com