5f4 really loud?

[chuckb]

Hey guys, my first 5f4 build is an awesome amp but is it common for this amp to be so loud? I mean when the vol is on like 2 or 3 it is loud. Is this normal for this amp? I would like to tame this beast's volume down some to a more comfortable level at lower settings ,is this possible? The amp seems like it's really loud to what it should be.

Chuck.

[klooon]

Hey guys, my first 5f4 build is an awesome amp but is it common for this amp to be so loud? I mean when the vol is on like 2 or 3 it is loud. Is this normal for this amp? I would like to tame this beast's volume down some to a more comfortable level at lower settings ,is this possible? The amp seems like it's really loud to what it should be.

Chuck.

Hi Chuck,

These amps are nice little beasts when it comes to volume. I am playing a Tubeking 5F4 clone and yes, it's loud, but not in such a way that you can not turn it up nicely from volume 0. I had this problem with my DIY 5E3 Deluxe, you turn it up, starts to make a sound at 2 and way too loud, turning it up further adds only more distortion, not more volume. This was with all 12AX7, humbuckers, 5Y3 that didn't drop enough voltage and a very efficient Eminence speaker (102dB), I went then for a 12AY7 less efficient speaker (this makes an enormous difference!) and also a NOS 5Y3. With your 5F4, you can try to change the 12AX7s to one, two (or even three) 12AY7. This should give you more control. (Please note that the perceived volume when starting to distort is still about the same, but it starts to distort then at higher volume knob settings). Further, also the treble and bass tone controls act as volume controls: if you turn these down the volume also drops. Please let me know how you get on.

klooon

[Chuck H]

Mouser sells Bourns "guitar" pots. They have an A10 taper. Which means that at 50% rotation they are only at 10% of the pots value. Most often when an amp is too fast on the volume control, that is, the volume comes on fast and offers very little adjustment in the clean range, the fault is in too fast a taper on the volume control. An A10 pot may help with this.

[Sleepthieves]

Mouser sells Bourns "guitar" pots. They have an A10 taper. Which means that at 50% rotation they are only at 10% of the pots value. Most often when an amp is too fast on the volume control, that is, the volume comes on fast and offers very little adjustment in the clean range, the fault is in too fast a taper on the volume control. An A10 pot may help with this.

Chuck that is awesome, I always wondered if there was something like that. Wasn't really sure how to find out. I have that issue with my 5F2-A and was wondering if some kind of different pot would help. Im gonna have to order some now, do you have a little more info on which model it is? Mauser's site doesnt seem to display the info A10 taper unless I missed something. Also is there a taper that would be at 25% of value at 50% rotation? Sorry if that is a real noob question.

[Chuck H]

http://www.mouser.com/ProductDetail/...6tr%252bcdM%3d

I mentioned "guitar pots" but that really isn't what you want. I did order these for a project and noticed that the "guitar pots" have too little rotational torque. They do sell the same pots with a high rotational torque as above (better for amps). The pots say "A10" on them but the data sheet and part number just call it an "A2" taper.

IIRC CTS pots are 25% taper and Alpha 1M pots are 15% taper. Alpha pots have different tapers for different values. 250k and 500k seem to be 25% but 1M is 15%.

[Sleepthieves]

Thanks Chuck couldn't have asked for a better answer.

[pdf64]

I'm sure that the standard CTS audio taper is 10%.
See 2nd bullet point
http://www.ctscorp.com/components/Datasheets/450sp.pdf

[Chuck H]

That's funny because it hasn't been that long ago that someone demonstrated that the CTS pots were 25% tapers. That's one reason new pots behave differently than the older ones then I suppose. I must have assumed the new pots are like the old ones because some people insist on using them as OEM. Which it seems they're not. Most often I would rather have a 10% anyway. I'll need to try those pots now. The taper on the Bourns product is a little abrupt and not so "logarithmic".

[pdf64]

Maybe the 25%ers were a special order? They'll make whatever spec you want for a min batch size of about 200!
The original BFs tended to be ~10% for bass (& mid if fitted), ~30% for treble and volume.
Pete.

[KFTG]

Klooon nailed it. The more efficient a speaker, the louder the amp will sound. There is the point about the taper of the volume pot. Get an audio taper 1 meg pot, and you will hear a more linear increase of volume as you turn it up. The loudness of the amp will still be there though, and if you want to fix that, then you need to use lower efficient speakers. Good luck.

[klooon]

Chuckb: are you still around??