What Specific Preamp Tubes did a 5E3 and 5F6a/5F8a originally came with?

[dreamingtele]

hi guys, I know tubes aren't really part of the bigger picture in comes of tone and all..

and I also know that Fender wasnt really consistent in the tubes they put in their amps, but I wanted to know what the majority of amps have?

I'm mainly interested on the 12AY7 (V1) and 12AX7 (V2) and 12AX7 (Phase Inverter) tubes.. what specific tubes? RCA? Telefunken?

If I want to get NOS ones, what specifically do I need to look for?

 

[archetype]

hi guys, I know tubes aren't really part of the bigger picture in comes of tone and all..

and I also know that Fender wasnt really consistent in the tubes they put in their amps, but I wanted to know what the majority of amps have?

I'm mainly interested on the 12AY7 (V1) and 12AX7 (V2) and 12AX7 (Phase Inverter) tubes.. what specific tubes? RCA? Telefunken?

If I want to get NOS ones, what specifically do I need to look for?

Tubes are part of the bigger tone picture. The circuit is the main determinant of tone, but all the bits and pieces (tubes, speaker, cabinet, etc.) sum up to the tone that the amp delivers.

Fender was consistent in what they put in specific circuits. As a circuit went through iterations, sometimes a tube in a specific position changed, but it usually changed to what was essentially a variation of the same tube.

For your third point, it really depends on the circuit. You can look at the circuits and see what tube types were used in specific positions. To address the examples in your subject line:

5E3

https://ampwares.com/schematics/deluxe_5e3.pdf

5F6-A

https://ampwares.com/schematics/bassman_5f6a.pdf

5F8-A

https://ampwares.com/schematics/twin_5f8a.pdf

Although there are variations and minor characteristics of tube types per the manufacturers that made them, nearly any US, EU, UK, or Japanese NOS tube is going to sound good if it's the correct tube for a specific position in the circuit. The main caveat is that long-plate 9-pin tubes can be microphonic and may not work well in initial gain stages.

 

[dreamingtele]

Tubes are part of the bigger tone picture. The circuit is the main determinant of tone, but all the bits and pieces (tubes, speaker, cabinet, etc.) sum up to the tone that the amp delivers.

Fender was consistent in what they put in specific circuits. As a circuit went through iterations, sometimes a tube in a specific position changed, but it usually changed to what was essentially a variation of the same tube.

For your third point, it really depends on the circuit. You can look at the circuits and see what tube types were used in specific positions. To address the examples in your subject line:

5E3

https://ampwares.com/schematics/deluxe_5e3.pdf

5F6-A

https://ampwares.com/schematics/bassman_5f6a.pdf

5F8-A

https://ampwares.com/schematics/twin_5f8a.pdf

Although there are variations and minor characteristics of tube types per the manufacturers that made them, nearly any US, EU, UK, or Japanese NOS tube is going to sound good if it's the correct tube for a specific position in the circuit. The main caveat is that long-plate 9-pin tubes can be microphonic and may not work well in initial gain stages.

Hi sir,

Thanks for the clarifications. its very informative!

I stand corrected in terms of my assumptions for the first 2 points.. thank you for that sir! I love this forum with these information available freely!

on the tubes, I was specifically looking for the exact tubes.. are they RCA 12AX7 or Phillips? or Mullard.. I'm not very knowledgeable on the NOS tubes, because I wasnt born during those times.. so I could be easily mislead to buying something thats different..

so I'm looking for specific ones the amps came with.. were the RCA tubes most used for this 50's era of amps? like every 50's fender amp got it?

Reason why is I want to try and buy them tubes and see how those preamp tubes make a difference..

 

[archetype]

Hi sir,

Thanks for the clarifications. its very informative!

I stand corrected in terms of my assumptions for the first 2 points.. thank you for that sir! I love this forum with these information available freely!

on the tubes, I was specifically looking for the exact tubes.. are they RCA 12AX7 or Phillips? or Mullard.. I'm not very knowledgeable on the NOS tubes, because I wasnt born during those times.. so I could be easily mislead to buying something thats different..

so I'm looking for specific ones the amps came with.. were the RCA tubes most used for this 50's era of amps? like every 50's fender amp got it?

Reason why is I want to try and buy them tubes and see how those preamp tubes make a difference..

There's really no way to quantify it, and there are no exact tubes, but it's likely that the majority of tubes in tweed, brown, black panel, and silver panel Fender's were RCA. The criteria for that selection were nothing more that lowest wholesale price and availability in quantity. There was no "Which brand has the best tone?" going on. Specific rectifier types were often Mullard due to availability.

Again, "...any US, EU, UK, or Japanese NOS tube is going to sound good if it's the correct tube for a specific position in the circuit." You can change tubes per different characteristics (short vs. long plate, plate type, low noise vs. standard) but the differences are minor and/or subtle.

If your main focus is just the IDEA of tubing an amp like it was originally, then do it. IMO that's a waste of time and money compared to simply installing good tubes that suit their positions in the circuit.

 

[dreamingtele]

There's really no way to quantify it, and there are no exact tubes, but it's likely that the majority of tubes in tweed, brown, black panel, and silver panel Fender's were RCA. The criteria for that selection were nothing more that lowest wholesale price and availability in quantity. There was no "Which brand has the best tone?" going on. Specific rectifier types were often Mullard due to availability.

Again, "...any US, EU, UK, or Japanese NOS tube is going to sound good if it's the correct tube for a specific position in the circuit." You can change tubes per different characteristics (short vs. long plate, plate type, low noise vs. standard) but the differences are minor and/or subtle.

If your main focus is just the IDEA of tubing an amp like it was originally, then do it. IMO that's a waste of time and money compared to simply installing good tubes that suit their positions in the circuit.

Hi sir!

Thanks so much! Yea. I think my goal initially was to tube the amp like it was originally, correct-for-the-era kind of thing.. but looking through your posts again, I do agree that it may not be worthwhile to pursue this..

I guess my main goal now is to put tubes as per schematic.. 12AY7 in V1, and 12AX7 in V2 and same for PI.. so I think I'll just try a bunch..

 

[corliss1]

Usually it's RCA for power and preamp, with some variation with the rectifiers, from what I've seen.

 

[archetype]

Hi sir!

Thanks so much! Yea. I think my goal initially was to tube the amp like it was originally, correct-for-the-era kind of thing.. but looking through your posts again, I do agree that it may not be worthwhile to pursue this..

I guess my main goal now is to put tubes as per schematic.. 12AY7 in V1, and 12AX7 in V2 and same for PI.. so I think I'll just try a bunch..

Excellent. Keep us apprised about your progress.

 

[BenTobith]

Tweeds would've likely used long/black plate RCAs for preamp. Smoke glass 6V6GTs, probably RCAs. RCA 6L6s.

 

[dreamingtele]

Tweeds would've likely used long/black plate RCAs for preamp. Smoke glass 6V6GTs, probably RCAs. RCA 6L6s.

Do you have a photo of this long/black plate RCA's?

 

[dreamingtele]

Excellent. Keep us apprised about your progress.

All I have are new production EHX 12AY7's and Tungsol 12AX7's... I have an incoming Sovtek 12AX7 LPS for PI as Ive heard they are great for that application, but I dont actually know if its true.. just based on internet lore.. LOL

I dont think there's anything wrong with my tubes actually.. but yeah, I was just curious IF getting period correct things make a difference..

 

[NTC]

Where 5881's were called for, apparently Tung Sol was the OEM brand. Gerald Weber claimed that in one of his books.

 

[BenTobith]

Do you have a photo of this long/black plate RCA's?

I have a few, I can grab photos later.

 

[rdjones]

All I have are new production EHX 12AY7's and Tungsol 12AX7's... I have an incoming Sovtek 12AX7 LPS for PI as Ive heard they are great for that application, but I dont actually know if its true.. just based on internet lore.. LOL

I dont think there's anything wrong with my tubes actually.. but yeah, I was just curious IF getting period correct things make a difference.

Several points to keep in mind.
The tubes available now (current/recent/modern production) that are marked "Tung Sol" and "Mullard" are nothing like the original US or UK made tubes that were used during Leo's time.
Leo never used Russian or Chinese tubes, period.

Branding - RCA, and to a lesser extent GE and Sylvania, were the big suppliers of "receiving" tubes.
But it was fairly common to find tubes rebranded, for example, tubes marked "RCA" with GE made internals ... and vice-versa. Sylvania also rebranded some UK and European tubes as "Made in U.S.A."
This became more common in later CBS years up until the end of US tube production.

Depending on the year/era of amp and the tube type in question - RCA, GE, Sylvania, Tung Sol and Mullard might be found in Fender amps. When CBS took over they had their own methods and preferences.

 

[dan40]

Instead of trying to find the exact brand of tube that was used, try to pick up a few from different parts of the World. For European 12ax7's, look for Mullard, Phillips and Telefunkens. For American made, look for Sylvania, RCA, GE and Tung Sol. You will notice some minor differences between the brands so it's nice to have a few different ones when trying to fine tune that last 5% of your amp's tone. The main draw with NOS and ANOS is their reliability as many amps from the 50's and 60's are still running with their original tubes.

The long plate tubes do sound good in certain amps, but they do tend to be more microphonic in combo amps and this is likely the reason that most manufacturers eventually moved on to making the short plate varieties. As for brands, Telefunken, Sylvania, Mullard, Raytheon and GE are some of the favorites but they are a bit hard to find these days and the price reflects that.