6SL7 5E3 - together at last?

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Can I use 6SL7 in the first and or second spots in the 5e3 circuit?

i have a couple of chassis' that have octal and 9 pin sockets and a small pile of 6SL7s. I was originally thinking of having the octal as the second gain/phase inverter stage, but I could have one in the first spot as well. Some have stated that resistor values can be swapped. Just replace the 9 pin socket that takes the 12ax7 and change to an octal socket, use the same values, and you are in business. Some post that using a 6SL7 in either spot is a poor idea. What's the truth?

I don't have a lot of experience in amp building, but I recently completed a 5E3 built in a donor chassis with donor transformers and it sounded great. I'd like to kick it up a notch, but I am not bright enough to do it without some input from the more informed.

Thanks for any guidance on this topic.
 
1st tube is a 12AY7, so it won't work well there without some changes. For the 12AX7 spot, it is probably fine. You might want to tweak some resistors, but it should work OK. These circuits are pretty tolerant.

Fwiw, I used a 6SL7 in a 5F2 type circuit instead of the 12AX7 and it sounds pretty good to me. Friends who are pro players say it sounds good to them, too.
 
The component values for both first and second tube are close to identical!

It will work dropping the 6SL7 right in. Nothing will break.

In guitar amps it´s all about TONE so there are no rights or wrongs. But they are all OK for 6SL7 in this amp. Listen to the amp and judge!

Also try the phasesplitter/poweramp from 5C3 that in my opinion is really charming.

Personally I prefer EF86 or a cascoded ECC88 at the input and use them in the amps I manufacture and use onstage but thats another story.
 
Wow, memories. In high school I had a 5D3, which was my main
hack-and-listen amp. The 5D3 is the earlier circuit with a 12AY7
and a paraphase splitter 12AX7. The 5C3 used a lower mu tube, I
think a 6SC7? mu of 70, just about where the 6SL7 is.

The change with the 5E3 was reconfiguring the 2nd socket to
a gain stage followed by a concertina splitter. It was done in
the late 50s so probably to suit people who wanted more gain.

I wanted more gain too, being a kid in the 70s, but I ended up
repurposing the mic input to a second stage and adding an AB-763
tone stack, so I had in essence a single AB-763 channel with 6V6
outputs (actually the phase splitter worked off local feedback still).
I still haven't heard a better sounding Fender if I do say so myself...

I think the 6SL7 would probably work fine in both spots, replacing
the 12AY7 in the first socket and the 12AX7 in the second, with about
the same or a little more gain. Nothing would catch fire for sure.

I used to like to go with a 220K instead of the 100K when swapping
a 12AX7 into a 12AY7 socket, maybe somewhere in between for the
6SL7, like 180K for starters but tune by ear for best tone. That's the
plate resistor, I think I left the cathode resistor alone.

What fun! makes me want to tear into my new model "Fender"
"Deluxe" that I bought because it reminded me of the old one.

Cheers,

Michael

PS Your question, soundwise, I think the paraphase 5C3 would
indeed sound different from the concertina 5E3 phase splitter,
but maybe the overall more gain of the 5E3 would make the biggest
difference. I always was partial to the paraphase circuit even though
it uses 2 sections so my fave is still 2 stages into the paraphase...

PPS I do think it's better sounding to use local feedback for the
paraphase. The AB-763 amps like the twin and bandmaster used
a global FB loop that I thnk may be detrimental to tone.
 
my "main" bass amp is a bassman clone (5B6). Cathode bias doesn't have the same power as the bands blackface bassman (aa165?) but killer tone with 2x12 cab. 2 12ax7's and National 6L6GC's.

I just finished a 5E8 (lower power twin) with 6sl7, 6SC7 and NOS TS 5881's (cathode bias). Again, killer tone.

I'd say determine your power requirements and tubes and build something from the fender field guide. You can't go wrong.

rick
 
There were 3 models of Tweed Pro amps, all with 6L6s and
3 nine-pin sockets.

The early 5D5 was like my old 5D3 but with 6L6s and the third
9-pin used to add another input channel ala the twin.
(paraphase splitter)

The 5E5 is like your 5E3 but with 6L6s and the twin input.
(2 stage concertina splitter)

The 5E5A has the gainstage + CF-driven tone stack of the 5E8 twin
plus the 2 stage concertina splitter, but uses only one tube for input.
Basically the 5E8 with one input tube. Most gain of the 3 I'd expect.

Now I have a lot of ideas for hacking my Hot Rod Deluxe...

Cheers,

Michael

PS as you see by now Fender did a lot of circuit/stage mix-n-match
and you can do more of the same to build your own flavor amps.
 
Trout said:



Does the 5E5 still get the volume control interactions as the 5E3?


5D5 Wide Panel

5E5 Narrow Panel

5E5-A Narrow Panel


Good point. The 5E5 has 2 input tubes, 4 channels, like the twin,
but the pairs are wired like the 5E3, not like the twin. The 5E5A
is wired like the twin. (The 5E5A schematic is missing something...
compare with the twin...)

It has to do with the tone stack. Seems the 5E3 and 5E5 volume
control wiring is to facilitate the tone control. The tone control on
these works differently on the mic channel; I think when you crank
the treble it only affects the instrument inputs. Nice if you are
actually using the mic input and playing Ventures or Surfaris
covers. But the volume controls do fight each other a little.

The 5E5A and twin tone stack is after the mix, so it affects both
mic and instrument equally, but the instrument has a brighter
tone overall. Volume controls are independent.

Michael
 
Michael Koster said:


It has to do with the tone stack. Seems the 5E3 and 5E5 volume
control wiring is to facilitate the tone control. The tone control on
these works differently on the mic channel; I think when you crank
the treble it only affects the instrument inputs. Nice if you are
actually using the mic input and playing Ventures or Surfaris
covers. But the volume controls do fight each other a little.

Michael

I find on the 5E3, that I use the High instrument jack to plug in guitar, use the volume knob to set my level (loudness) a bit more than needed,
then raise the mic channel volume to its upper range (7-10) and it attenuates the signal and seems to bring more (smoother) bass in. It is actually very effective.

On the mic channel, when using a guitar, the treble response is not nearly as good, however, it is better (crisper)when the tone knob is set near 6-7 instead of max. There seems to be a sweet spot there.

The 5E5-A is a heck of a lot like the 5E7 tweed bandmaster also. Looks to me like Leo recycled that topolgy on many models.
I have a 3 X 10 5E7 on the bench, what a monster!

I would love to find a way to reduce the bass without changing out all of the coupling caps, I have .05's in already.

IMO anything over 6 on the bass knob gets a bit flubby even with a bigger bassman OT installed.
I have a tweak that makes the bass control infinitly more linear, but I have not tweaked the cap value yet.
 
If you add a socket to your 5E3 you can do the 5E5A topology.

Wait this is 2008.. If you have an original 5E3...

On the 5E5A they stole the 2nd input socket to add the gainstage
+ CF driven tonestack, then feed the gainstage + concertina,
as in the 5E8 Twin. Those must have nice gain, even with 12AY7s.

Another difference, the Pro amps had a single rectifier and the Twins
had parallel 5Y3s going to parallel 5U4s.

Michael

I just pulled the back off my Hot Rod Deluxe and it has 3 9-pins
and room for a fourth. The PCBs could come out and be replaced with
directly mounted sockets, pots, and a tagboard. Hmm where to put
the rectifier tube(s)...
 
Going back to the 5E5-A circuit,

In playing around a while back, I had changed a connection on the bass pot that made the control very linear compared to the original.

The original seemed to only respond at the lower portion of the pot, and did nothing from 50-100%.

Using the mod below, now it is fully linear in response, but I have yet to determine what cap value to use. Anything over 75% the bass still gets flabby just like the original did, just a wider more controllable range.

Question is, higher or lower value cap?
 

Attachments

  • tweedbassmod.jpg
    tweedbassmod.jpg
    62.1 KB · Views: 286
The component values for both first and second tube are close to identical!

It will work dropping the 6SL7 right in. Nothing will break.

In guitar amps it´s all about TONE so there are no rights or wrongs. But they are all OK for 6SL7 in this amp. Listen to the amp and judge!

Also try the phasesplitter/poweramp from 5C3 that in my opinion is really charming.

Personally I prefer EF86 or a cascoded ECC88 at the input and use them in the amps I manufacture and use onstage but thats another story.

If you would please, post some schematic of any ecc88 designs, i have a pile of these and been wanting to use them for guitar.
 
Maybe time to just breadboard a 6dj8 for guitar and see. I did make a socket adapter once and it didn't work good, forget actually what the problem was. It may have been 6SC7 grid leak bias and i tried to swap a 6dj8. I think a 6dj8 phono stage would be a good start. Noone i know uses them for a guitar preamp stage and there is most likely a good reason why.
 
I ended up staying with the stock values and used the pot wiring change. It seemed to keep that big open sound that way.
Bonus,, the bass pot responded better.
Cons; the bass pot at its minimum did reduce the volume ever so slightly.

I still have it that way, have not opened that amp up in years now!
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.