Any tips for taming a wild 5E3?

[slim66]

So, I built my 1st 5E3.  I used P-TGP-002 PT and a Hammond 1750-H OT.  The 1st filter cap is 33uf, and the power tube cathode resistor is a 10w, along with a 50v power tube bypass cap.  The rest of the circuit is standard.
     Going into a Celestion G12M 65 watt speaker, this thing is too loud with the volume at 1.  Also, like most 5E3's, it starts grinding at @2, and just keeps getting more grindy after that.

     What can I do to tame it a bit?

Thanks, 

Slim

[isaac_teller]

If you have a 12AX7 in V1 try a 12AY7 instead. If still too much' try a 12AU7.

[pdf64]

Voltage survey?
Volume pot taper?

[slim66]

Thanks.  Volume pot taper is audio.

Voltage survey:

V1

pin 1. 176.9
pin 3. 1.23
pin 6. 169.2
pin 8. 1.23

V2

pin 1. 153.1
pin 3. 1.2
pin 6. 194.8
pin 7. 14.65
pin 8. 39.12

V3

pin 3. 319
pin 4. 294.1
pin 8. 16.27

V4

pin 3. 316.7
pin 4. 295
pin 8. 15.93

B+

1.  323.6
2.  293.5
3.  233.7

Thanks again.

Slim

[passaloutre]

What speaker do you have in it? Too loud is a common problem for people thinking a 5E3 is crankable anywhere except on a stage, especially with most guitar speakers.

I'm actually quite satisfied with Robinette's 1/4 Power switch: https://robrobinette.com/5e3_Modifications.htm#Quarter_Power_Switch

I have it mounted in a little box inside the back of my cabinet so I can switch from practice mode to stage mode.

I also really like my 5D3 Deluxe with an inefficient 10" speaker. That one is crankable in the garage.

Edit: I see you mentioned the Celestion Creamback, which is 97db. If you go to a Jensen P12R or P12Q, at 94db, it'll sound like half the watts. If you want to keep the British sound, Celestion also make the "Peacekeeper", with a sensitivity of 86db!

[sluckey]

I'm actually quite satisfied with Robinette's 1/4 Power switch

Clever!

Da Geezer has another clever circuit that operates by manipulating the bypass caps on the output tubes. Very effective. See page 7 of my amp scrapbook.

     https://sluckeyamps.com/misc/Amp_Scrapbook.pdf

[passaloutre]

Yes I’ve used something like that before also, but a simpler implementation. It sounds good!

[tubeswell]

Robinette's 1/4 Power switch: https://robrobinette.com/5e3_Modifications.htm#Quarter_Power_Switch

That's Fender's switch - not Rob's. He plagiarises everything and calls it his.


(Fender put it on their Eric Clapton Tremolux)

[tubeswell]

To tame a 5E3


Use lower gain tubes in the preamp (5751 or 12AY7 in V1, and/or 12AT7 in V2)
Ditch one or more of the preamp cathode bypass caps.
Reduce coupling caps to 22nF (instead of 100nF)
Attenuator

[pdf64]

Robinette's 1/4 Power switch: https://robrobinette.com/5e3_Modifications.htm#Quarter_Power_Switch

That's Fender's switch - not Rob's. He plagiarises everything and calls it his.


(Fender put it on their Eric Clapton Tremolux)

To be fair, Rob doesn't claim any responsibility for it, rather he writes "This very cool 1/4 Power Switch is from the 20 watt Fender Eric Clapton Tremolux".

[passaloutre]

To be fair, it's just a fixed L-pad, which surely is older than Robinette, Clapton, or even Fender

[bmccowan]

Just mentioning a couple of other options.
 - Since it's cathode biased, a simple VVR is an option. I think Trinity amps still sells a board. I've done it a few times and it works well, although if you turn it down really low the amp loses character.
 - A cheap attenuator. In a weak bourbon fueled moment I ordered a Bugera. But it actually works quite well.
Both options are argued about - just like everything in tube amps!