Preamp Tubes? - Who, What, When, Where, Why, and How?

[MartyStrat54]

I manage a Music Store in the Midwest..........You don't know how many old Organs where offered to me *For FREE* that I turned away in the last 19yrs *shakes head*...........I am such a dumb ass. thing is I knew they where full of tubes but I wasn't playing a tube amp so it never acured to me AHHHHHHHHHHHHHHHHHHHHHHHHH

I just put on some Carpenters and started crying over what you said. I don't know what makes me feel worse. The fact that you didn't recover any of the tubes, or the fact that the organs went to the dump and all the pretty tubes were lost forever.:eek2::eek2:

 

[wegman]

I live in the country and we have a landfill where we take our garbage. I now take our garbage every Sat in the hope that I will score another orphaned organ. So far I have come up empty.

 

[RiverRatt]

I just found a line on a free Baldwin Model 5 organ - I think that's one of the good ones. The people who have it don't answer their phone. I've left messages and email!

Edit: Nevermind. It uses 43 6SN7s. The power amp and Leslie cabinet would still be sweet, but what in the hell do you do with 43 6SN7s?

 

[MartyStrat54]

Man, that's an old organ. A 6SN7 was the forerunner of a 12AU7. You got to remember that a tube with a mu of 15 was hot shit back in 1940. Many audiophile's still use 6SN7's in their tube amps.

Here is a good quick read.

The 6SN7 - the best general-purpose triode?

I'm also going to look into this book, Sibley, Ludwell, Tube Lore. It came out in 1996 and covers all tubes including obscure ones. Sounds interesting.

Those 6SN7's do have a market albeit not like a 12AX7.

 

[LuredMaul]

I just put on some Carpenters and started crying over what you said. I don't know what makes me feel worse. The fact that you didn't recover any of the tubes, or the fact that the organs went to the dump and all the pretty tubes were lost forever.:eek2::eek2:

The worst part for me is; It's not like I don't know... It just never clicked in my head because I wasn't into it.....not because I didn't know tubes where valuble.

I'm 38 and I even remember tube checkers in drugstores n things

 

[Bret138]

I've been on the forum a while..haven't had a chance to get into this thread yet though..

sorry if there is a current discussion going on in here i was just seeing if anyone has some suggestions for me..

I'm thinking about re-tubing a JMP 1987S I picked up a few months ago..

I was thinking NOS for pre-amp, and CP for power tubes because I go through those somewhat quickly..

I'm going to go by a store here in manhattan (they claim to have a pretty decent selection) just to see what i can find

dBm- We Got TUBES!!!

any suggestions from their list..or any suggestions at all would be appreciated!

 

[RiverRatt]

It wasn't just organs that went into the dump. TVs, Hi-Fi sets, console stereos, table top radios, all had the potential of having some nice audio tubes in them. My dad bought an estate last year - an old farmhouse with barns, ponds, etc. He told me there was an old TV in the barn. It had to have been going on 50 years old. I still managed to salvage a GE 6BQ5 from it. There's a friend of mine who's mother-in-law ran a motel for the last 50 years. She has a big basement room that's full of old TVs and stuff. I got a couple of them and they were 1970s Japanese junk, but there's also supposed to be an old console stereo in there. Might be good for a few 6BQ5s if it's the right age.

I'm getting hung-up on this Raytheon black plate thing. I know I'm obsessing, but I only have 1!

Marty, I emailed Terry to see if he had any Raytheon BPs, and he has to check his stock, but he says even better are the yellow letter high-gain short plates. $30 per tube. Do you know anything about these? I don't think I've ever seen one except for a 12AT7.

 

[MartyStrat54]

Well they only list part numbers and brands, there is no price given on any of them, so it is hard to say if the prices are fair.

The preamp configuration is a little different in your amp. However, you need a solid tube in V1 and that would be a Telefunken or an Amperex. In V2 an American made Raytheon Black Plate in V2. Then a Sylvania or GE in V3.

If you ever do decide to go NOS for the power tubes, it's hard to beat Mullards. You can get RFT's for a reasonable price as well and they sound great.

 

[Bret138]

yeah thats exactly why I came here before i went by the store. I was just going to write down everyones suggestions then price check them at the store and go from there..

 

[MartyStrat54]

Marty, I emailed Terry to see if he had any Raytheon BPs, and he has to check his stock, but he says even better are the yellow letter high-gain short plates. $30 per tube. Do you know anything about these? I don't think I've ever seen one except for a 12AT7.

Well I think you would agree with me that the tube is going to sound different, right? Short plate versus long plate, gray plate versus black plate. And what makes all of them high gain? If they have yellow letters and short plates they are all high gain?

These are the later production Raytheons. Similar to the era of Racko's tubes. Remember the yellow letter Raytheons later became the MIJ Raytheons.

Terry may be trying to sell you what he has versus what you want. Those short plate Raytheons are okay, but they do not sound like a black plate.

 

[RiverRatt]

Bret, the problem a lot of us are going to have is that we use DSLs and TSLs which have four preamp tubes and have picked out preamp sets accordingly. IIRC, with a 3-tube preamp like the 1987, you have one gain stage per channel on V1, and V2A is the second gain stage for both channels. If you jump the channels, you get all 3 gain stages. (Someone please jump in if that's wrong - I'm never 100% sure).
Raytheon black plates, Mullards, Matsushitas, RFTs, Telefunken, Amperex, Brimars, etc. are all favorites here, but they all have their own voice. It's hard to say what you will like. The ideal thing to do would be to buy as many as you can afford and decide on your own.
If you want my recommendation, I would try a medium-gain smooth plate Telefunken in V1, a high-gain Raytheon black plate in V2, and V3 (the phase inverter) can be whatever you want. I prefer to use a high gain tube in V3 as well. It doesn't affect the tone so much as it opens the amp up.

 

[guitarmartin416]

The Tele's


The GE's


The RCA's




SCORE!!!!!!!

The rest of the Mullard and Tele's and Rca's are in my amps

 

[RiverRatt]

Niiiiccceee. I would really love to see more of that RCA in the bottom right corner. It looks like a clear top in the photo. Does it look something like this:

If it is the same, that's a sweet tube for V1 (provided it's still good). If you don't like it, drop me a PM and we might work out a sale/trade if you're interested.

 

[guitarmartin416]

Niiiiccceee. I would really love to see more of that RCA in the bottom right corner. It looks like a clear top in the photo. Does it look something like this:

If it is the same, that's a sweet tube for V1 (provided it's still good). If you don't like it, drop me a PM and we might work out a sale/trade if you're interested.

Ya, clear top, 12au7a

 

[RiverRatt]

My bad. I thought they were all 12AX7s.

 

[guitarmartin416]

My bad. I thought they were all 12AX7s.

lol.... the rest of them are. Let me know if your interested in any. I'm outta work for the winter, so I may part with some. Unfortunately I used the best ones in my other amps! i.e. Tele-RCA-Sylvania-Mullard

 

[Bret138]

Thanks guys, I'll see what i can find at that store today or tomorrow and go from there!

 

[RiverRatt]

lol.... the rest of them are. Let me know if your interested in any. I'm outta work for the winter, so I may part with some. Unfortunately I used the best ones in my other amps! i.e. Tele-RCA-Sylvania-Mullard

Nah, I've got 8 or 10 AU7s lying around, and most are cleartops. The AX7s are quite rare, but there's a 12AU7 under every rock.

I've been trying to find a cheap and easy DIY project like the Firefly 1-watt amp or the Matsumin Valvecaster boost pedal to use up some of my 12AU7s. The firefly uses the AU7 for an output tube, and the Valvecaster is a boost pedal that uses an AU7 as the driver. It uses a 9-volt wall wart for power, or you can actually run it off a 9-volt battery!?!?

 

[guitarmartin416]

I'm goin to check on a '30's Crosley console radio for 30 bucks, lets see what tubes i can come up with.

 

[MartyStrat54]

Well if it's a 30's model, there won't be any 9 pin tubes in it. It will be all octal base tubes. Back then most of the power tubes had a metal case instead of glass, such as an original 6L6.

Yeah, there's old and then there's too old. Some tube collector might want some of them strictly for their age whether they work or not, but you are not going to find any RCA 12AX7's. They didn't come out until 1947 and a 12AU7 came out a few years before that. I think right after WWII.