Time and energy haven't permitted the continuance of my single-ended 6V6 marvel, so I figured I would tear into something I alluded to in the last post.
The Pignose G40V Combo amp.
I sort of picked this up on a "researched whim".
What web-scribes I could find on it indicated that it had some very old-school "brown" grit to it, and in fact, was almost hard to play clean.
Well I had been eyeing this puppy in the pawn shop for several months. Bigger rigs came and went, but this lingered. After it had gathered enough dust, the proprietor decide to reduce it to well South of 100 clams, so I was on-board for a 100% tube amp.
Topology of this little guy indicates a 6L6 Push Pull (presumably biased AB1) power section with a rather busy 3 stage front end, driver section, cathode follower tone (bass, mid,treble) and gain/master volume controls. It also sports a presence knob to de-bleed some of the negative feedback. so I would call it a hot rodded Plexi front-end (12AX7's) firing into a Fender Vibrolux.
Bear in mind, I am talking circuit topology, not build quality.
Indeed, even with single-coils this thing was hot, fat and wet. Anything over 9 o'clock on the gain started some serious compression and loose vintage grit. Even playing modestly clean it would compress and sing for what seemed like hours.
Only problem was it also received WEW out of Del Rio Texas (and any other station that was strong enough). Further schematic rooting indicated that indeed, like very antique Fenders this thing had no buffer resister up to the grid of V1a, the input was wired directly to the grid.
I figured a little buffer would kill some of the RFI and leave the crush, so I wired a salvaged 15K carbon resister in series and sure enough, no more del rio.
Most of the compression and mushy overload stayed intact.
I am currently using it as my practice amp, and I continue to be amused at:
. How loud it can get (I'm guessing an honest 35 watts through a 10" generic speaker).
. How much old-Fender crush it can build on the front end (Fenders did it out back).
. How tactile it is, you can pull-back and be sensitive or tear-in and sound really PO'ed, without ever turning a knob.
More later
Thursday, November 13, 2008
Sunday, November 2, 2008
A single-end to my search?
Been a long lonely-lonely time.
Still being in search of the perfect tone has taken through many, very creaky doors and down more than one detour.
(no wonder people do these side-turns with their faith too)
Additional roads traveled have been:
Some guy had boxed this puppy up into a homade cabinet with a very vintage Bogen ceramic magnet tiny-wattage 12" speaker. What I could reverse-deduce of the schematic indicated a two-stage preamp (plus driver) via 2-12AX7's force-feeding a 6V6GT which was (uniquely?) cathode biased through an axillary winding on the secondary of the output transformer.
Little guy sounded pretty good, tight and chimey with lots of gristle cranked up to pat. pend.. Since we are talking a single-ended 6V6 machine (at likely reduced voltages) I would be surprised if it was kicking 4 watts, so this was at almost "have a conversation" volumes.
I wanted to build my own thang though so I came up with a hybrid schematic with 3-preamp stages plus a driver, with the last preamp stage having a cathode-follower tone stack w/ 3-band EQ. As an FYI, this is a cash restricted R&D project, so I am even salvaging tube sockets from the old unit. I did treat it to new pots and switches though.
Here is the start of the project:
Still being in search of the perfect tone has taken through many, very creaky doors and down more than one detour.
(no wonder people do these side-turns with their faith too)
Additional roads traveled have been:
- Digital guitar modeling (a now antique Digitech RP-50, cool reverb and delay effects).
- The organic Tube Screamer TS-9 (mine dates to the early 1980's) force-feeding the front-end of various small amps such as an Estey Magnatone 104 ($2 at a yard sale some years back) and the Prince-tone.
- Most recently blowing through a Pignose G40V tube amp (the ultimate Brown-Soun machine, but that's another post).
Some guy had boxed this puppy up into a homade cabinet with a very vintage Bogen ceramic magnet tiny-wattage 12" speaker. What I could reverse-deduce of the schematic indicated a two-stage preamp (plus driver) via 2-12AX7's force-feeding a 6V6GT which was (uniquely?) cathode biased through an axillary winding on the secondary of the output transformer.
Little guy sounded pretty good, tight and chimey with lots of gristle cranked up to pat. pend.. Since we are talking a single-ended 6V6 machine (at likely reduced voltages) I would be surprised if it was kicking 4 watts, so this was at almost "have a conversation" volumes.
I wanted to build my own thang though so I came up with a hybrid schematic with 3-preamp stages plus a driver, with the last preamp stage having a cathode-follower tone stack w/ 3-band EQ. As an FYI, this is a cash restricted R&D project, so I am even salvaging tube sockets from the old unit. I did treat it to new pots and switches though.
Here is the start of the project:
Tiny box doesn't leave a lot of room, so I've burnt a knuckle or two so far.
I'm getting ready to finish out the power supply currently, and then to the preamp section, so it will get quite a bit busier in here.
More to come.
Friday, March 21, 2008
Bass-mating
The little YBA-2A awoke from its' slumber painlessly. The cabinet was a no-name and unrated for power capacity, but pulling the jack-plate off (infinite baffle deal) revealed a very large ceramic magnet, and based on the size I was figuring the driver for a 2" voice coil, so this little jewel was good for 75-100 watts.
The good news was I would never blow this cabinet with my weenie 18-20 watts. The bad news was I would never get the speaker to contribute to the tone.
None-the-less, I played. The little amp was smooth and sultry up to about 4-5 on the dime dial, and thereafter crunch set in.
With single coils, by the time you hit 8 on this little monster it was howling like a two year old with a lolly-pop 5" out of reach.
This little guy would peel paint, especially if you were packing the front-end with a tube screamer.
But of course, I:
a. Now have a family and a mortgage
b. have neighbors
I used to laugh at 18 watts, but I was playing bass in a hyper-db. band at the time (just this side of a jet aircraft taking off). I am here to now say 18 watts is LOUD.
Like most tube amps, it doesn't walk the walk until you dime it. So I was still sort of looking for a tone machine solution.
Enter amp-modeling options, stage left.
The good news was I would never blow this cabinet with my weenie 18-20 watts. The bad news was I would never get the speaker to contribute to the tone.
None-the-less, I played. The little amp was smooth and sultry up to about 4-5 on the dime dial, and thereafter crunch set in.
With single coils, by the time you hit 8 on this little monster it was howling like a two year old with a lolly-pop 5" out of reach.
This little guy would peel paint, especially if you were packing the front-end with a tube screamer.
But of course, I:
a. Now have a family and a mortgage
b. have neighbors
I used to laugh at 18 watts, but I was playing bass in a hyper-db. band at the time (just this side of a jet aircraft taking off). I am here to now say 18 watts is LOUD.
Like most tube amps, it doesn't walk the walk until you dime it. So I was still sort of looking for a tone machine solution.
Enter amp-modeling options, stage left.
Tuesday, March 18, 2008
...been a while
Holidays and work pressed (work continues to) but I've still been the voice of one wailing in the wilderness.
... So here are my current disjunct thoughts.
Various frustrations with the old Prince-towns' reverb circuit finally led me to dissect the thing and have another looksee.
Turns out in one of my soldering swarays I had melted the binding-post for one of the reverb drive-coils off the bobbin, and it subsiquently broke the (28 gauge?) wire attached.
no connection - no signal.
So while I lamented no 'verb, and dreaded the amp's dry sound (fenders are all about 'verb), I broke the traded-into Traynor YBA-2A "Bassmate" out of the closet.
Years back, I was playing bass in church, and all the equipment I had was way overkill.
Not inconsequentially, the guy leading worship had this amp (piggy0back deal) with a little 115 Traynor reflex cabinet.
I had some 112 monitors I wasn't using, so we struck hands and made a deal.
I found out early on the amp wasn't long on headroom for bass (has a pair of EL-84's in the output, so it 'may" throw 20 watts on a good day). I also found out, however, that sonic qualities when driven to distortion with a guitar, were much like an 18 watt Plexi Marshall.
A few recent drive-bys on the pawn-shops and I found a generic single 12" PA cab (no tweeter) or $30, and I had a mini stack with my little freebee plex-clone out of storage and getting hot again.
More on Trayning wheels later.
... So here are my current disjunct thoughts.
Various frustrations with the old Prince-towns' reverb circuit finally led me to dissect the thing and have another looksee.
Turns out in one of my soldering swarays I had melted the binding-post for one of the reverb drive-coils off the bobbin, and it subsiquently broke the (28 gauge?) wire attached.
no connection - no signal.
So while I lamented no 'verb, and dreaded the amp's dry sound (fenders are all about 'verb), I broke the traded-into Traynor YBA-2A "Bassmate" out of the closet.
Years back, I was playing bass in church, and all the equipment I had was way overkill.
Not inconsequentially, the guy leading worship had this amp (piggy0back deal) with a little 115 Traynor reflex cabinet.
I had some 112 monitors I wasn't using, so we struck hands and made a deal.
I found out early on the amp wasn't long on headroom for bass (has a pair of EL-84's in the output, so it 'may" throw 20 watts on a good day). I also found out, however, that sonic qualities when driven to distortion with a guitar, were much like an 18 watt Plexi Marshall.
A few recent drive-bys on the pawn-shops and I found a generic single 12" PA cab (no tweeter) or $30, and I had a mini stack with my little freebee plex-clone out of storage and getting hot again.
More on Trayning wheels later.
Wednesday, October 31, 2007
Anniversary Memories
October 3O marked the 14th anniversary of my marriage to my lovely bride, and today (the 31st) marks the 30th anniversary of my acceptance of Christ's call and my following him through baptism.
To this day, both are dear to me.
Both mark acceptance that I didn't really believe I merited, and both relationships go out of their way to encourage me in my worth.
I get reflective around these times, and it occurred to me to ask myself - have I really done justice for either relationship? For Christ; do I take enough opportunity to reflect and realize that He authored me, binds me together and causes me to draw this very breath that allows me life here and now?
For my wife; do I show the woman that chose to hitch her wagon to my train the consideration and thoughtfulness that she merits?
Both show me grace - overtly and abundantly - and I am indebted to both more than I can explain, or perhaps even fathom.
Here I stand.
Not particularly proud of the decisions that get to here in my life, but not particularly embarrassed either.
Not embarrassed as life has given me ample opportunity to look around, look outside of myself and see that I am not exceptional. We all require grace on many levels.
My prayer to my Maker:
Keep me reflective, please, of what is forgiven me through You and that You desired this fellowship enough that you called me accountable in the first place.
My thoughts to my wife:
I am sure that I have neglected our relationship many times, and yet we are together.
I express my thanks to you for your perseverance and the hope that awakens in me.
May I always be more like Christ tomorrow than I am today, for the sake of my Maker and all who know me.
To this day, both are dear to me.
Both mark acceptance that I didn't really believe I merited, and both relationships go out of their way to encourage me in my worth.
I get reflective around these times, and it occurred to me to ask myself - have I really done justice for either relationship? For Christ; do I take enough opportunity to reflect and realize that He authored me, binds me together and causes me to draw this very breath that allows me life here and now?
For my wife; do I show the woman that chose to hitch her wagon to my train the consideration and thoughtfulness that she merits?
Both show me grace - overtly and abundantly - and I am indebted to both more than I can explain, or perhaps even fathom.
Here I stand.
Not particularly proud of the decisions that get to here in my life, but not particularly embarrassed either.
Not embarrassed as life has given me ample opportunity to look around, look outside of myself and see that I am not exceptional. We all require grace on many levels.
My prayer to my Maker:
Keep me reflective, please, of what is forgiven me through You and that You desired this fellowship enough that you called me accountable in the first place.
My thoughts to my wife:
I am sure that I have neglected our relationship many times, and yet we are together.
I express my thanks to you for your perseverance and the hope that awakens in me.
May I always be more like Christ tomorrow than I am today, for the sake of my Maker and all who know me.
Friday, October 26, 2007
Guinea Pigs and Wheel Alignments
No, the guinea pig wasn't tracking wrong, but the beat-up old Mercury wagon was.
5 years after I installed an inner tie-rod end on it, I decided it was time to get it aligned (wanted to make sure we were going to keep it, as I hate wasting money).
Small, nondescript chores like this are usually what fill days off around truck-boys household.
That and irritating the boy with his own guinea-pig.
(the guinea pig did pull to the left a little, after I installed her in the bathroom with my boy).
Use-it or lose-it vacation. This phenomena probably spawns more ill-conceived household projects than Tim (the tool man) Taylor on amphetamines.
It's a rough balance to achieve:
You've got no money for a real vacation (maybe breakfast at McDonalds) so you figure you'll tangle with projects you've left lay around for a while.
You have no money to do these right either, so it becomes a love of labor.
So I spend my $59.95 to have the wheels put in some semblance of alignment (Vs. the 5-year old tape-measure job it had) which may squeeze a few more miles out of (the next set) the tires.
Sure enough, this thing had more toe-in than a kid checking the temperature in a swimming pool.
Drives better now and the beauty is I didn't destroy anything else in the process.
So ends another successful vacation day.
5 years after I installed an inner tie-rod end on it, I decided it was time to get it aligned (wanted to make sure we were going to keep it, as I hate wasting money).
Small, nondescript chores like this are usually what fill days off around truck-boys household.
That and irritating the boy with his own guinea-pig.
(the guinea pig did pull to the left a little, after I installed her in the bathroom with my boy).
Use-it or lose-it vacation. This phenomena probably spawns more ill-conceived household projects than Tim (the tool man) Taylor on amphetamines.
It's a rough balance to achieve:
You've got no money for a real vacation (maybe breakfast at McDonalds) so you figure you'll tangle with projects you've left lay around for a while.
You have no money to do these right either, so it becomes a love of labor.
So I spend my $59.95 to have the wheels put in some semblance of alignment (Vs. the 5-year old tape-measure job it had) which may squeeze a few more miles out of (the next set) the tires.
Sure enough, this thing had more toe-in than a kid checking the temperature in a swimming pool.
Drives better now and the beauty is I didn't destroy anything else in the process.
So ends another successful vacation day.
Monday, October 22, 2007
Piddley Cruiser plight
Saturday found us a break in the rain, so rather than go secure gopher-wood for the arc I figured I would do some preventative maintenance on the residential fleet.
We drive an '03 Chrysler Piddley Cruiser with a stick-shift. It's been a good car to date but a few months back picked up a chirping fan-belt tensioner pulley, so repairing this was on the docket.
It proved rather difficult to get the pulley off (no room to get the bolt out) and after trying 3 parts-stores I found out why.
The pulley isn't available by itself.
So in effect, I was supposed to spend $80 dollars on an entire tensioner assembly to alleviate a noise in a $2.00 bearing molded into a 39 cent plastic wheel.
I'm no fiscal guru, but this seemed a little overkill.
End result:
I found out with the proper dental tool you can pick the seal out on an idler-pulley bearing and repack it. I lucked out on this because the bearing was just dry, not yet damaged. So the net repair was only a dollop of moly-lithium grease.
Good thing guitars don't have idler pulleys.
The moly grease would sure get your pants messy.
We drive an '03 Chrysler Piddley Cruiser with a stick-shift. It's been a good car to date but a few months back picked up a chirping fan-belt tensioner pulley, so repairing this was on the docket.
It proved rather difficult to get the pulley off (no room to get the bolt out) and after trying 3 parts-stores I found out why.
The pulley isn't available by itself.
So in effect, I was supposed to spend $80 dollars on an entire tensioner assembly to alleviate a noise in a $2.00 bearing molded into a 39 cent plastic wheel.
I'm no fiscal guru, but this seemed a little overkill.
End result:
I found out with the proper dental tool you can pick the seal out on an idler-pulley bearing and repack it. I lucked out on this because the bearing was just dry, not yet damaged. So the net repair was only a dollop of moly-lithium grease.
Good thing guitars don't have idler pulleys.
The moly grease would sure get your pants messy.
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