Help! Need the tube layout for a 65Amps London Pro (Solved - Thanks!)

Discussion in 'The Squawk Box' started by 2manyGuitars, Sep 15, 2018.

  1. 2manyGuitars

    2manyGuitars Senior Member

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    I just picked up this used London Pro today and I'm looking to retube it. I pulled out the existing ones and I'm not convinced they were in the proper spots. The 65Amps website seems to be down so no help there.

    From what I can gather, it's supposed to come with 2 x EL84, 2 x 12AX7, 1 x EF86, and 1 x 6CA4. Here's what I pulled out and the positions they were in...

    65aLP01.jpg

    According to the only image I could find on the net, this doesn't match up.
    From - https://www.premierguitar.com/articles/65amps_London_Pro_Amp_Review

    65aLP03.jpg


    For you amp geniuses, here's what the guts look like...
    (I tried up loading a larger version but it keeps shrinking it down. If you need a bigger one, PM me.)

    65aLP02b.jpg

    The sockets in the last photo line up with the sockets in the other 2. The controls from left to right are;
    - Volume for the EF86 channel with pull boost
    - Tone for the EF86 channel with pull bright

    - Mini-toggle to select channels

    - Volume for the 12AX7 channel
    - Tone for the 12AX7 channel

    - Master volume/voltage (shaft only since knob is missing)

    - Standby, power light, power switch

    Thanks in advance.
     
    Last edited: Sep 15, 2018
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  2. RAG7890

    RAG7890 Premium Member

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  3. 2manyGuitars

    2manyGuitars Senior Member

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  4. efstop

    efstop Senior Member

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    The 6CA4 is a rectifier, the EF806SG is an EF86 variant, and the ECC803S is a 12AX7 variant. The pinouts are different between the 12AX7 and the EF806 so if they fit, those ones are likely ok. The photo labeling might be alphabetical, there :)
     
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  5. 2manyGuitars

    2manyGuitars Senior Member

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    I already checked that the EF806 and ECC803 were variants. I have no idea how old those tubes are so I’m replacing them (with the proper tubes) but I want to make sure they’re in the proper spots.

    Any site showing the specs for this model seem to have copy/pasted from MusiciansFriend.com where they only mention 5 tubes. And even then, they just say “tube rectifier” and don’t specify which. They only show one 12AX7. There’s a site that sells a complete tube set for the 65Amps London (higher end model). That’s where I got the “supposed” setup for this one.

    I know from searches that there are a few members on here that own one of these and am hoping that one of them chimes in.
     
  6. matthew bear

    matthew bear Senior Member

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    your power section is labeled correctly( you picture, not the PG layout) but I'm not sure of the pre amp section.
    the way you pulled them out makes the most sense, as the EF 806 in the first gain stage is the most logical. there would be no reason to use it elsewhere, as they are known to be fussy, but sound glorious. that's all I got :dunno:
     
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  7. matthew bear

    matthew bear Senior Member

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    I'm 99% sure you had it correct from the get go.
     
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  8. 2manyGuitars

    2manyGuitars Senior Member

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    Thanks. As far as the preamp section, all the info I could find on this amp talks about the 12AX7 channel and the EF86 channel. And they never mention a third preamp tube but like I mentioned earlier, the other London amp seems to share the same tube set. I assume the extra 12AX7 is for either the pull-boost or pull-bright on the EF86 channel.
     
  9. matthew bear

    matthew bear Senior Member

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    Th
    the 3rd tube is a phase inverter. I think you're good :thumb:
     
  10. matthew bear

    matthew bear Senior Member

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    I'm fairly certain the amp wouldn't work if the ef86 and the ecc83 were backwards, the ef86 has a different pinout.
     
  11. 2manyGuitars

    2manyGuitars Senior Member

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    As part of the deal, I got them to throw in a new set of tubes. They only had 4 of the 6 so they knocked another 50 bucks off. Now I have to find an EF86 and the 6CA4. I probably won’t have any luck locally so it’s off to the interwebz.
     
  12. matthew bear

    matthew bear Senior Member

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    Your rectifier shouldn’t need replacement per se, unless there is an issue... it does what is does, no tonal distinction to speak of. The ef86 will affect things, couldn’t hurt to some variety on hand. I’m not a huge tube roller, but if your amp sounded good to begin with, why change the tubes? Regardless I’d look for some ef86 tubes as a backup/ tone Funtime exploration...
     
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  13. 2manyGuitars

    2manyGuitars Senior Member

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    Thanks for the tip on the rectifier. Now if I can’t track one down right away, I won’t be too worried. Hey, I just play ‘em. I’m not that knowledgeable on what makes them tick.

    I just picked up the amp yesterday so I’ve only tried it out at the store. It sounded great but there was a bit of buzz and also a noticeable volume difference between the two channels (could be normal :dunno:). With these types of amps (point to point, hand wired, quality components) 99% of the time, most issues are likely tube related. Plus, it’s 5 years old and for all I know, so are those tubes. I used the old “well, first thing I’m going to have to do is buy a whole new set of tubes for it” as a bargaining chip. It got me 4 new tubes and a 50 dollar discount so I may as well swap all 6 and start fresh.

    I will likely get a couple different EFs (or variations) as I’ve heard those have a tendency to go microphonic pretty quick. Apparently, not as much in heads vs. combos, but...
     
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  14. matthew bear

    matthew bear Senior Member

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    Sounds like a plan, I’d want some extra Ef86 tubes around if I had any amps with them... that would be your only odd ball tube to worry about.
     
  15. mrdannyboy

    mrdannyboy Senior Member

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    I have some awesome old stock EF86 is you need. ANd others lol

    DId you get this figured out.
     
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  16. 2manyGuitars

    2manyGuitars Senior Member

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    Yeah, I was able to get in touch with someone who owns the same amp. He confirmed left to right;

    EF86 - 12AX7 - 12AX7 - EL84 - EL84 - 6CA4

    I figured I'd post that here in case someone ever googles "London Pro tube layout".

    I'll definitely PM you about those tubes. I wouldn't mind having a few options to choose from. Thanks
     
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  17. mrdannyboy

    mrdannyboy Senior Member

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    you Still around. I pm'd you bro. Cheers
     

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