Does it matter how many tubes?

[Pycroft]

Hi all...

As many know, I'm looking for a preamp, and am considering tubes. Question: Does it matter how MANY tubes there are? I was lookign at something like this: http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

It only has two inputs, and it's small. I've seen big ones with lots of electronics, and 5 or more tubes. Does more always mean better?

James

[disneyjoe7]

Just my $.02 here... but I think a tube addes 99.3% to tubeness, every other tube addes .004%.

[mhardy6647]

Hi all...

As many know, I'm looking for a preamp, and am considering tubes. Question: Does it matter how MANY tubes there are? I was lookign at something like this: http://cgi.ebay.com/ws/eBayISAPI.dll...=STRK:MEWAX:IT

It only has two inputs, and it's small. I've seen big ones with lots of electronics, and 5 or more tubes. Does more always mean better?

James

For strictly line level, I would opine that two is plenty (e.g., one two-section triode like a 6SN7 per channel); three if the rectifier is a vacuum tube. An ADC vacuum tube preamp designed by Mark Deneen (with phonostage) that passed through my abode some time ago had I]thirteen [/I]6DJ8s (6922s) in it! Some of those were active cathode loads for others in a strictly dual-mono configuration -- but that is a LOT of circuitry for a fairly simple tube preamp!

[tonyb]

Like anything else, build quality, parts used, has a say in the matter also, not just the amount of tubes. Lots of variables to consider.

[SolidSqual]

One tube for each channel is usually pretty good when done correctly. That being said, when you start adding tube rectifiers and other good stuff like that, greater performance can be had. I agree with Disneyjoe's sentiment, but I would modify it to say 99.3% with a tube per channel.

[mhardy6647]

FWIW, some stuff on vacuum tube linestages from one of my favorite vacuum tube amp designers.
http://www.the-planet.org/linestage2.html

[tonyb]

http://cgi.ebay.com/Cary-Audio-Elect...item4a9e1dbf31

Nice plain jane starter unit.

[SolidSqual]

http://cgi.ebay.com/Cary-Audio-Elect...item4a9e1dbf31

Nice plain jane starter unit.

It's cheaper than the cheapest Chinese alternatives too.

[Pycroft]

What,on average,would something like that go for? 200? 150? I don't want to pay more than it's worth. Thanks for the link. I look on audiogon, ebay, craigslist every day, but don't know enough about this stuff to make an informed decision. Thanks, and if you see anything else you think may work, don't hesitate to post it :)

James

[mhardy6647]

I peeked at that LRE preamp auction link. That is a high-gain preamp with EQ for MM phono/tape head use, not a "linestage". It is, in fact, more or less a copy of the classic Shure MM preamp. It's not what the OP is looking for (as best I can tell).
http://www.vinylengine.com/library/shure/m65.shtml (registration required to d/l docs)

I am lobbying for an EICO HF-85 :-)
http://www.audiokarma.org/forums/sho...highlight=Eico

EDIT: Yeah, the Cary "AES" stuff was/is nice, basic equipment at reasonable prices. Used to be available as kits; wish they still were!

Speaking of kits, here's a couple of possible options if the OP isn't afraid of a little bit of solder/rosin fumes:
http://www.bottlehead.com/store.php?...on=show_detail
http://www.transcendentsound.com/preampkit.htm

[Pycroft]

Hardy -

TRUST ME...you don't want me to have to put together ANYTHING! I take my crap to George's just to clean it because I don't want to take the top off myself. I may look at something wrong and screw it up :)

So no to the Lafayette. I can't plug a CD player into the input for the 'tape' for example, and use it?

[Pycroft]

Still not sure what this means, "That is a high-gain preamp with EQ for MM phono/tape head use, not a "linestage". It has inputs for tape and phono based on the pictures. I can't just plug the RCA IC's from the SACD player in to the tape side to make it work? What am I missing?

[Face]

line stage=no phono stage

[mhardy6647]

sorry. what he said. You want a line-level preamp for a CD player or what-have-you.
The "Tape" inputs on that thing are for a tape HEAD (very low level signal, like a moving coil phono cartridge) not a tape DECK such as you're used to (which has preamp and EQ circuitry built in).

Ask Mr. Grand to build the preamp for you; I'm sure he'll be happy to!

[Pycroft]

Alright...So tape = bad, but there is a switch in the front of the Lafayette preamp (Maybe not one online, because the seller sent me a few more) that you can switch from Phono to Tape. If I do not have a turntable, and plug my SACD into the phono side, would that be okay?

Picture attached...sorry if this is redundant, but I've never heard some of the terms you guys are using :)

[Pycroft]

And while you're all into answering my dumb questions...what is NOS when referring to tubes?

Thanks :)

[Wardsweb]

And while you're all into answering my dumb questions...what is NOS when referring to tubes?

Thanks :)

NOS = New Old Stock

[Wardsweb]

If you know what a soldering iron is you can build one of these Bottlehead battery powered tube pre's for about $100. It doesn't come with a cabinet, you have to buy or fab one.



A very simple circuit

[tonyb]

Bid on that Cary, Jimmbo, has cd inputs, nice starter unit as I said, and for the money, a no brainer. For under 200 bucks and not wanting to build one, quality used tube pre's are gonna be scarce.

[Pycroft]

Tony,

I bid pretty much my max...I am high bidder, but haven't met the reserve. I guess the seller doesn't think it's as entry level as everyone else :)

[madmax]

Oh man, I would pick up that Lafayette if you can. I won't out bid you but I think its pretty cool. It is VERY old. About 40 years ago when I was a child I got the same one but in the form of a pair of mono's from some really old guy who said they were very old. I never did figure out what they were for. I remember the internal parts were minimal which is a good thing. Now I realize they might have been special. I notice that one has phono marked on it so it may have a phono preamp built in.
madmax

[Pycroft]

Regarding the lafayette, what specifically can I ask him to figure out if it would work in my situation?

Thanks,

James

[mhardy6647]

The Lafayette has a very high-gain ("powerful" if you will) preamplifier with special equilization (like a tone control) to take the very low level (about one millivolt) signal from the tape head on a tape recorder and amplify and equalize it up to a "flat" signal of about 1 volt to feed a "line-level" preamp or power amp so you can hear the sound on the tape. Your SACD player has a "line-level" analog output (about 1 volt, often more, actually, on modern digital sources) that, if you fed it into either input of that little Lafayette, would result in a bad sounding and distorted output.