5G9 Different V1 tubes FWIW

[tubeswell]

Don't know if these'll all load up but tried experimenting with different V1 bottles this morning to get an idea of how they distort on power chords and go on clean trem in my recent 5G9 build.

I tested EH12AY7, GE12AT7WA (JG6201 with 'aerofoil' plates and triple spacers), GEJAN5751 (Grey Plate), Philips 12AX7 (MiniwattECC83 made in Holland)

First up is the power chords with different bottles with and without channel jumpers

[tubeswell]

And the rest

My take on these clean ones, (which I finger-picked as opposed to using a geetar pick) I think I prefer the 5751 and 12AX7 for bluesy tone. The Eh 12AY7 was a bit thin for finger picking, (but sounds okay strummed). The GE12AT7 was almost the same as teh Eh but not quite as thin. The Philips12AX7 does clean clinically good with nice bright top end and good balance, but somehow the 5751 (alhough not top-of-the-line) to my ear has a tad more vintage bluesy flavour.

(Now I better get back to looking at the power tube section)

[Paul P]

I also prefer your 5751, which I'd never heard of before.

Just out of curiousity, how loud is your amp in the first batch of power
chords ? My amp, which should be a lot less powerful than yours, is too
loud for comfort with the volume turned up 30-40%, with no distortion
in sight.

Or are you using a pedal ?

Paul P

[tubeswell]

Hi Paul P

No not using a pedal. The amp is uncomfortably loud if it is at full vol, and seeemed to be even louder when I had it biased at 28mA but I've got id idling at 22mA at the moment. I think I've become innured to loud noise a bit.

No pedals, just straight into the amp with the vols maxed out. Due to the wiring of the vol pots, if you turn both pots to max, the vol goes down slightly (unless the channels are jumpered), but if you back off the pot of the channel that you're not directly plugged into by about 1/4 of a turn, the amp gets to its loudest for that channel. I understand this is a characteristic of these dual input channel tweeds.

[Bruce / Mission Amps]

Yikes

What speaker is in the amp?
I know this sounds negative, I'm not negatively critiquing you, but all the selections, regardless of the tubes, have a high mid freg glassy clatter that, well, ... I'm sorry, it really sounds bad to me.
Almost like the power tubes are idling too cold and being driven into class B territory... or maybe the sound of an inexpensive mic picking up the sound of slappy, strings/frets and pick noise from a very cheap guitar being played with hard smacking pick attack.
I know it is very hard to tell on the PC here but I wouldn't be happy with the amp tone on any of the clips from those mp3 files.
Is it just me?

[tubeswell]

Hi Bruce

I did have the amp biased at 31mA and it sounded better. Then I got heaps of feedback that it was way to hot, so i backed it off to 22mA. And it has sounded thin ever since. I am biasing it using a 1R resistor over the cathode to ground. I am fairly confident that the 1R is actually '1R' on each cathode - The resistors are 1% metal film and I have used 2 x 2R in parallel for 'each' 1R resistor, to further reduce any possible variance from 1R. Furthermore each parallel set measures 1.6R on my meter, and when I cross the leads on my meter they measure 0.6R.

The guitar is an '89 Fender Strat (US made), admittedly I haven't changed the strings for about for two months. I don't think there's a quality issue there.

The speaker with the overdriven clips is a worn out OEM eminence speaker with a Soldano sticker on the back of it.

the low quality recording is me-being-lazy using the built in mic on the eMac, and was prompted by a suggestion that I try a few different pre-amp tubes to get different distortion before looking at circuit tweeks

There is an earlier .mp3 clip I did with the tubes biased at 31mA (using the same guitar and lazy recording setup and this speaker in it) and before I realised that I'd left one of the 1M resistors out of the trem circuit (the 1M is series with the Depth Pot input) under this post.

http://music-electronics-forum.com/s...9696#post59696

Just to digress, since putting the 1M in series withe the depth pot input, it seems to have tamed the intesity of the depth control - but I'm thinking that maybe I liked it better without the 1M or maybe I'll biff in a 470k in that location instead.

The speaker on the clean clips is a reconed Alnico bulldog that has been rated at 35W RMS - maybe too overrated. I know the tone is not what what I am after yet so I am going to put a switchable cathode bias in (when I get a couple of spare hours)

[Bruce / Mission Amps]

Hi Bruce...

There is an earlier .mp3 clip I did with the tubes biased at 31mA (using the same guitar and lazy recording setup and this speaker in it) and before I realised that I'd left one of the 1M resistors out of the trem circuit (the 1M is series with the Depth Pot input) under this post.

http://music-electronics-forum.com/s...9696#post59696

Just to digress, since putting the 1M in series withe the depth pot input, it seems to have tamed the intesity of the depth control - but I'm thinking that maybe I liked it better without the 1M or maybe I'll biff in a 470k in that location instead.

The speaker on the clean clips is a reconed Alnico bulldog that has been rated at 35W RMS - maybe too overrated. I know the tone is not what what I am after yet so I am going to put a switchable cathode bias in (when I get a couple of spare hours)

OK... I listened to the other clip and although not as bad, I still can hear that raspy, very high mid "klispsh" tone to the front end of most of the notes.
This is nearly impossible for me to tell if it is the recording process/equipment, the guitar, the actual speaker, the amp or the power tube idle condition.
If you don't hear it in person then I would suspect the mic overloading or the recording method... etc.
Regardless, unless I mistook or misread your actual plate to cathode voltage, you could take my idle current advise and run the power tubes a little hotter.
I like the deeper CCR type trem.

[tubeswell]

I took the Alnico bulldog out and put in a 2nd-hand eminence OEM 30Wer and it sounds much better. The bulldog was to highly rated (70W) and was to tight and not giving good all round freq, or good breakup. I think a Jensen 12PQ will also be better.

I also put a 5U4G in for the recto instead of the 5U4GB. I think the 5U4G delivers 225 mA (instead of 270). Haven't measured it, but it seems to sound a teency bit more saggy and syrupy now.