Bugera V5 >>> 5F1 Conversion

[charisjapan]

As I mentioned in Hackworth's Champ 600 to 5F1 Conversion Thread Champ 600 to 5F1, I want to try and use my first "all-tube" combo as "body donor." ("innards recipient?") I have the C600RI too, but I don't 'dislike it' enough to gut it! But the Bugera, which was ear-opening when I got it, soon got thrown in the attic. I probably couldn't get much for auction because there's lots of them already out there, sometimes getting unloaded for $20.

So, I got the $29.99 Boothill 5F1 board kit, and already have most of the parts necessary, so let's see if I can make it produce quality tone, not that muffled, blaaahh sound it now makes...



This is the insides: SS rectifier, 12AX7 preamp, EL84 power. It has a 3-step attenuator which sounded yucch, and a reverb also yucch. The two-pot volume/gain didn't really 'gain' anything. The tubes are probably not top-quality, speaker, too. But the cab is pretty nice!

[charisjapan]

Before I start dismantling and chopping, a few questions about trannies:

My preamp voltages were like 170VDC at pins 1&6, and 1.05VDC at pins 3&8. I haven't thoroughly studied about EL84s yet, but the heater is 4&5 with 6.5V (same as preamp heater), about 310VDC at pins 7&9, and 9.9VDC at pin3. Are these numbers compatible with changing to a 5F1 using a 6V6? Oh, yeah, the PT numbers: the 2 oranges were 3.2VDC/3.6VAC, the reds were 100mVDC/19VAC and black 1mVDC/.002VAC. Yellows were 130VAC/153VDC and 146VAC/153VDC. I didn't know which should be AC, which DC.

I identified the SS rectifier array as Hackworth said, a line of 4 small diodes on the lower left of the picture, with output of 155VDC. There is also an array of 4 larger diodes upper right with like 6.5V numbers, what's that?

I appreciate any help, and hope I can use PT and OT!

[hackworth1]

That PT is perfect for the job. All the numbers are right on. You have lots of room and you can install a 5f2 tone control with the extra pot hole.

Retain the exisiting switch. No need to relocate it. A step bit comes in handy to increase hole diameters where needed. From left to right, I would do this:

Switch, Chassis mount fuse holder, 6.3V Fender style pilot light, 1M tone control, 1M vol control, two input jacks.

Use a 1 1/16 chassis punch to cut a hole for a 6V6 power tube near the center of the chassis. Check for optimum location w/o speaker interference. One of the two existing holes for the noval sockets should be used for your 12AX7 preamp tube. Probably the one on the lower right.

Your board must be elevated with standoffs of some kind to keep it high enough off the tube sockets. Your sockets will be located "under the hood" so to speak. You will be able to lift the board and prop it up when you solder your pin connections.

Make up a separate diode rectifier board and mount it near the PT.

[charisjapan]

Originally Posted by hackworth1

That PT is perfect for the job. All the numbers are right on. You have lots of room and you can install a 5f2 tone control with the extra pot hole.

Retain the exisiting switch. No need to relocate it. A step bit comes in handy to increase hole diameters where needed. From left to right, I would do this:

Switch, Chassis mount fuse holder, 6.3V Fender style pilot light, 1M tone control, 1M vol control, two input jacks.

Use a 1 1/16 chassis punch to cut a hole for a 6V6 power tube near the center of the chassis. Check for optimum location w/o speaker interference. One of the two existing holes for the noval sockets should be used for your 12AX7 preamp tube. Probably the one on the lower right.

Your board must be elevated with standoffs of some kind to keep it high enough off the tube sockets. Your sockets will be located "under the hood" so to speak. You will be able to lift the board and prop it up when you solder your pin connections.

Make up a separate diode rectifier board and mount it near the PT.

Hackworth,

Sounds like I'm on a roll! My wife saw the Bugera in pieces, so I told her I'm 'fixing' it. Which is a LOT like the truth!

I have standoffs right there in the center of the Bugera board, which is now waiting to be cannibalized. I doubt if there's many more parts that I will use, but anything that appears useable will go in the parts bin. I have a step bit for everything 'cept the octal. I may end up nibbling that out (Ouch! my hand already hurts)

(Wait a minute! Didn't I say I wasn't gonna mess with an existing chassis again?! )

I compared both 5F1 and 5F2a layouts, and it looks like I'll need another 16uF cap and a couple of small ceramics, right? Anything else?

[keithb7]

Re: 5F2A...A tone knob, a power supply cap, a smaller tone bleed cap for the tone knob, a cap for in between the volume and tone pot,and a micro switch for NFB.

Oh...And a bat to beat the grin off your face!

[charisjapan]

Originally Posted by keithb7

Re: 5F2A...A tone knob, a power supply cap, a smaller tone bleed cap for the tone knob, a cap for in between the volume and tone pot,and a micro switch for NFB.

Oh...And a bat to beat the grin off your face!

(ouch!) ... still grinning!

While I'm adding an NFB, is it possible to add a tonestack cutout switch for 5F1 convertibility? Ceriatone does that with their Vibro Champ clone, and if it's only a switch, I think that would be a nice option.

Would it work to just have a switch cut the connection between the center lug of the volume pot and the 500pF cap?

[ludashoeless]

im about to do the same with a champ 600 but im waiting for the 600 to get here before i buy the kit. im interested to see the rectifier. i know how to make it, but would i have to make my own turret board? and i want to see where you put yours. good luck!

[charisjapan]

Originally Posted by ludashoeless

im about to do the same with a champ 600 but im waiting for the 600 to get here before i buy the kit. im interested to see the rectifier. i know how to make it, but would i have to make my own turret board? and i want to see where you put yours. good luck!

I have some 1cm perforated board for turrets, and I will use that. Since I need something for the extra 16uF cap if I follow the suggestion to make a 5F2a, I'll just make it a little longer and place it between the PT wires and the 5F1 board. So yeah, you have to have some kind of board to mount it. It's only about 30mm X 60mm size. In Hackworth's 600 thread, he has a link to a reverb build which has pictures of an eyelet setup, and search "rectifier" by 'JBennett' in Advanced Search for another build. I'll be posting pictures in a little while of what I make, too!

Here's what a made with MSPaint to clarify the layout:

[muchxs]

Originally Posted by charisjapan

Since I need something for the extra 16uF cap if I follow the suggestion to make a 5F2a, I'll just make it a little longer and place it between the PT wires and the 5F1 board.

You don't need the extra cap. The 5F2 power supply is just different not necessarily better. Think of it as a 5F1 with a tone control. You can build it up on a 5F1 board with the extra parts on the pots.

You don't have to build it with a 6V6, either. Way I figure it you'll need to punch a bigger hole for the octal socket. If you want to keep the EL84 just substitute a 250 ohm resistor for the 470 ohm resistor, wire it up like a tweed otherwise. A 7189 can be substituted for the EL84. Again, not necesaatily better just different.

[keithb7]

I built my 5F2A circuit on a 5F1 board. Was an easy fit, getting the extra cap on the board. Even though Boothill does not advertise a 5F2A kit, he was my supplier by adding just a few extra parts to his 5F1 kit. My board looks a little tighter than the a stock 5F2A, but there was really no hassles.

Stock here with plenty of room:


Here is mine on a 5F1 board:

[icy_wind500]

Everyone is turning everything into 5F1s !!!!

[muchxs]

Originally Posted by icy_wind500

Everyone is turning everything into 5F1s !!!!

Nope. I'm working on a 5F2 right now.

I can't show you 'cuz it's a customer's amp.

Look at a straight up 5F2 schematic. Compare it to 5E1 'cuz both use a choke.

http://www.webphix.com/schematic%20h..._5f2_schem.pdf

2x 16uf in parallel = 32uf = more than a 5Y3 should see. Use 1x 22uf.

[icy_wind500]

Do 5F1 and 5F2 sound much different?

[TheNewSteveH]

I just posted about the same idea, over at Amp Garage. Someone pointed out that I ought to listen to the Bugera through a decent speaker before gutting it.

[andyfromdenver]

Originally Posted by muchxs

You don't need the extra cap. The 5F2 power supply is just different not necessarily better. Think of it as a 5F1 with a tone control. You can build it up on a 5F1 board with the extra parts on the pots.

You don't have to build it with a 6V6, either. Way I figure it you'll need to punch a bigger hole for the octal socket. If you want to keep the EL84 just substitute a 250 ohm resistor for the 470 ohm resistor, wire it up like a tweed otherwise. A 7189 can be substituted for the EL84. Again, not necesaatily better just different.

Noted too. Thank you!

[hackworth1]

I concur with muchxs on everything he said.

1.) You don't need the extra Filter Cap. My advice: Don't.
2.) Build it with the Little 9 pin British Style Power Tube if you want to.
Since you need new chassis mount tube sockets anyway, you can:
a) make a bigger hole for a 6V6 and use the 470 ohm Cathode Resistor you
already have.
(you might need a good excuse to buy a 1 1/16" chassis punch, right?)
b) use an existing hole for the EL84 and get a 250 ohm 5 watt resistor.

Andy, please share your view/opinion about a 5F1 and the AC-4 you built.

[muchxs]

Originally Posted by hackworth1

(you might need a good excuse to buy a 1 1/16" chassis punch, right?)

Octals generally come in three sizes.

'60s Fender is 1" hole, 1 1/2" mounting centers. Boot Hill sockets fit '60s Fenders.

1" hole, 1 5/16" mounting centers. Pretty common. Around half of the vintage and NOS octals are 1" hole, 1 5/16" mounting centers.

1 1/8" hole, 1 1/2" mounting centers. 1.125" hole for those who don't like fractions. Around half of the vintage and NOS sockets are 1 1/8" hole, 1 1/2" mounting centers. Tweeds use these.

Those who are payin' attention notice that the BF / SF sockets are kinda weird and not very common. Good thing Boot Hill sockets fit.

Belton or Omron sockets are around 30mm hole, 1 1/2" mounting centers whatever that works out to in millimeters. 37mm mounting centers? Mojo punches their chassis for metric octals.

[charisjapan]

Originally Posted by muchxs

Octals generally come in three sizes.

'60s Fender is 1" hole, 1 1/2" mounting centers. Boot Hill sockets fit '60s Fenders.

1" hole, 1 5/16" mounting centers. Pretty common. Around half of the vintage and NOS octals are 1" hole, 1 5/16" mounting centers.

1 1/8" hole, 1 1/2" mounting centers. 1.125" hole for those who don't like fractions. Around half of the vintage and NOS sockets are 1 1/8" hole, 1 1/2" mounting centers. Tweeds use these.

Those who are payin' attention notice that the BF / SF sockets are kinda weird and not very common. Good thing Boot Hill sockets fit.

Belton or Omron sockets are around 30mm hole, 1 1/2" mounting centers whatever that works out to in millimeters. 37mm mounting centers? Mojo punches their chassis for metric octals.

Much,

Hehe! Just spent the last 30 minutes googling and checking my local Japanese suppliers... they said the same thing. Trouble is, finding anything inch size is nearly impossible. Closest I could get was a 5-pc set 18, 20, 22, 25, 30mm with bolts, $100. I have a step-drill bit up to 20mm, and might end up nibbling out the rest, simply because it's not that crucial. As long as the hole is big enough, and the mounting holes are solid, the socket/tube won't go anywhere.

Of course, I wasn't planning on doing this any more at all, so perhaps I should just break down and buy the set and get it over with!

[boredguy6060]

Harbor freight has a step drill that goes up to 1 3/8ths that only cost about 10bucks, if I remember right it also came with a smaller step drill.

Step drill require a lot of deburring compared to a punch, but they are cheap. If your going to need to bore 50 holes then a punch would be best, but if you may only need to use it on rare occasions then a step drill makes more sense.
How hard is it to get one online from Harbor freight, or get someone to buy it and mail it to you?

[charisjapan]

Originally Posted by TheNewSteveH

I just posted about the same idea, over at Amp Garage. Someone pointed out that I ought to listen to the Bugera through a decent speaker before gutting it.

Y'know... duh!

Thank you for the suggestion, man. I hooked it up to a cab I bought a while back for peanuts, and it sounded actually pretty good! Before I go all gung ho, I might try a speaker swap. I was going to change the speaker anyway, so...

What I'm thinking about is 2 X 5" 8-ohms that I got from this 605 MIK Fender cabinet. I already re-wired this for 2X 4-ohms and 4X 8-ohms, and think this cab with just the 4 speakers might be a good home for the 5f1/5F2a I was contemplating. decisions, decisions...

If I do stick with the Bugera as is with the 2 5" speakers, I'm pretty sure I should change out the tubes. I have a couple nice 12AX7s, and can get EL84s at my local supplier. They don't have any NOS, but stock Electro Harmonix, JJ, and the Sovtek EL84M, which they say is a 7189 replacement for the Matchless sound. Any suggestions?