More sparkle for 5e3

[rockybottom16]

I'm looking to get a little more sparkle out of my 5e3. I have 400v on the plates of the JJ tubes that are in there now(w/250 ohm cathode resistor). Would changing to EH tubes and uping the cathode resistor to 300 ohms add any high end?

I've changed the coupling caps to .022 and the bypass cap of V1 to 4.7 and the bass is well under control. So I'd like to add some high end without reducing the low end anymore.

The current speaker is a recent G12H Celestion. I've never noticed this speaker to be lacking in the sparkle department when I've used it in other amps. And I like that it's real efficient. I tried an old Jensen P12r before in another 5e3 I had. It had lots of sparkle, but came up short in terms of volume. I'm not unwilling to try a different speaker, but I need it to be efficient.

Thanks!

[pdf64]

What's your guitar, pedals; good low capacitence cable?
What amps get closer to the tone you want?
What vol/tone settings are you using on the 5E3? Tubes?
Have you tried it with a real celestion blue? A G12H30 is close, but a blue is likely to be a noticeable improvement.
Sparkle is more of a BF type tone quality, but as long as you aren't maxxing the controls out then there may be some room for getting it closer to where you want it to be.

[ThermionicScott]

Some folks consider the JJs to sound a little darker than the alternatives, so switching to EH tubes is one option -- I'd reduce the B+ a little first.

You might consider reducing the V1 cathode cap further, perhaps below 1uF. Because of its place in the circuit, you shouldn't lose very much bass, but more of the midrange will be "shelved out", leaving the treble boosted by the cap.

- Scott

[cminor9]

did you replace all 5 of the coupling caps or just the first two? I found that replacing the first two with .022 wasn't enough so I put .033 and .047s in the later stages. Also slightly tweaked the cathode bypass cap on the first stage (6.8uf iirc). Have a Weber Blue Dog (their take on a Blue). I find that with a bright guitar, I can actually run the volume knob at about 8 and it's ok. Plenty of sparkle (high end treble).

But I guess it depends on what you mean by sparkle. There is still a lot of mid to it, but that's really the character of the amp; it's not a blackface. It would take some serious tweaking to get a more "scooped mids" blackface sound.

[guitarmike2107]

you could also try a partial bypass on the second triode to boost just the high "sparkle" frequencies i.e. use two caps on the second stage, one larger cap with a resistor to partially boost everything, and one smaller cap to fully boost the highs

[rockybottom16]

Thanks for the suggestions. You got me thinking and it's occurred to me that it's been almost a year since I had a 5e3 around; and guess what amps I've been playing with since then? Yup. One of them's a blackface Super and the other is a tweed princeton I built last year. Both of them are very bright and sparkly. Maybe I'm subconsciously trying to make the deluxe sound like my other amps. (?) I think another thing may be that I've been playing at real low volumes since I got the 5e3 up and running last week. Today I had a chance to crank it up for the first time, and once it started breathing fire I forgot all about sparkle. And with the thump of that G12H one would never know all that grunt was coming from a 12 watt amp. Now I remember why I like these little monsters. ;-0

I think I will lower the voltage a little and get some EH tubes at some point. I've got a BOSS EQ pedal that works pretty good for scooping some mids if I need to. It sounds so good cranked up that I don't want to mess with it too much. Cheers.

[rockybottom16]

you could also try a partial bypass on the second triode to boost just the high "sparkle" frequencies i.e. use two caps on the second stage, one larger cap with a resistor to partially boost everything, and one smaller cap to fully boost the highs

Mike- This sounds interesting, but I'm not as well versed in electronics as most of you. Could you elaborate a little in terms of where exactly to put these caps? Are you talking about the bias circuit for V2? I think there's a 25uf cap and 1K5 resistor there now.

[guitarmike2107]

Well I wouldnt say I am well versed in electronics either, but this is fairly simple to experiment with.

For more sparkle I think you want to boost above 10kHz, the problem with doing this thought is that as the gain is turned up it may cause fizz. but you have to try to see.

I assume you understnad that by using smaller capacitors accross the cathode resistor causes the bass to not be boosted as much as the treble. you can have a look at this website to get an idea as to how different cathode capacitors effect the frequencies boosted. The Valve Wizard -Cathode Follower

so what I would try is to put a 0.047uf cap accross the 1.5k resistor, that would fully boost the "sparkle" content, then put a 25uf cap in series with a 25k trimmer and also place that in parralell with the 1.5k resistor, adjust the 25k trimmer to get the amount of boost where you want it.. easy.