What the hell.....

[wingnut1]

It might solve some of the reliability issues HRDs have, but it would still sound like a HRG.

[Kap'n]

Success!

The "5E5 mod" did exactly what I wanted. Just enough volume. Had the Gretsch with the Bad Bob permanently on all night, and got all the shades of clean and dirt at the right volume. Only kicked the Mule on once or twice for an over the top solo.

Output transformer stayed relatively cool. I could hold my hand on it.

The best part - it probably weighs less than a 1/2 pound more than the 5E3.

[ziess]

Awesome, I might just try that myself.
Do you have that schematic lying around, I can't seem to find it.

Tommy.

[Kap'n]

I'll try to do an updated one this weekend.

FYI - a GZ34-type Copper Cap has slightly more sag than a real Mullard, about 7 volts in this case.

[ziess]

Thanks Kap'n. I've a spare WZ34 and some TS 5881s lying around so I might give it a try to keep me out of trouble 'til the 6A20 arrives.

Tommy.

[yankeerob]

I'll try to do an updated one this weekend.

FYI - a GZ34-type Copper Cap has slightly more sag than a real Mullard, about 7 volts in this case.

Hey Kap - I'd be interested in having a look at that too - BTW - I tried to email you some stuff on the 1watter but it bounced back - if you send me an email I'll reply with our drawing and the info it's based on...

[Kap'n]

The updated schematic.

I didn't fix it in the schematic, but I've got the 100 ohm/virtual centertap filament wiring.



This version is a rock and roll machine. Much more high end available, which I'm guessing is due to the higher plate load than normal (6.6Kohms?). With the Bad Bob this thing kills.

[ziess]

Nice one, thanks.
Blown your OT yet?

I tried a WY3 Copper Cap in my 5F6-A today at rehearsal. It sounded, y'know, alright, if a little harsh.

Tommy.

[Kap'n]

Blown your OT yet?

Not yet. Ted said he thinks it should take the heat. I think the windings themselves are pretty beefy. I'm guessing the smaller size of the OT also helps shape the low end to give it a more aggressive rock voicing.

The OT that's in there was just sitting around doing nothing anyway.

I'd be pretty pysched if it doesn't blow. But I'd get over it if it does. It's all in the name of science.

[ziess]

Yup, they're pretty cheap if it does decide to die. Have you decided if it's any louder than stock yet?

Tommy.

[Kap'n]

Have you decided if it's any louder than stock yet?

Yes it is, and the tone is more cutting. Not loud enough to get any weird artifacts with the speaker (12A125 - 20W, light dope), but enough to get the whole synergy of tube/speaker breakup.

I'm speculating that I'm probably getting ~20W out of it, but I don't have the tools to do an accurate measurement. Not that it matters.

[yankeerob]

Hey Kap - now that I've cleared a few things off the bench - I'm gonna have a go at the 'What the hell' model - do you think a JJ 7591 S'd be a reasonable substitute for a 6L6GB?- spec - oh yeah and that cap in parallel with the 10W 270Ω is a...?

[NTBluesGuitar]

The originals are 25uF/25V. Maybe do 25uF/50V?

[yankeerob]

Nice one Teej - I heard a guy with a real deal '57 5E3 on Sat night and it was singin' - dude could play mean bottleneck too - goes by the name of Gwyn Ashton... from New Zealand or somewhere that way... Probably gonna go with a tube recto on this one for the mojo - whatya think about the 7591 idea? I'd like to find a new production tube that's gonna 'fit'...

[stratcat55]

If you go ptp and dump the the drive channels on the HRDlx, it wouldn't be bad. The clean channel is actually pretty decent with a tube change. But a 5e3 would be better and more versitile, not a one trick pony. I may just push the shit out of my HRDlx till it goes up in smoke convert it to a 5e3 and save the money on the chassis cabinet. Yeah, that's the ticket........

[NTBluesGuitar]

I may just push the shit out of my HRDlx till it goes up in smoke convert it to a 5e3 and save the money on the chassis cabinet. Yeah, that's the ticket...

If you keep the iron, it would be like a 5E5. Almost the same thing, but it would be LOUD for a 5E3.

I guess you could put new iron and tubes in there do to it as a 5E3...kind of big for a 5E3 cabinet, but I bet it would still sound good.

[yankeerob]

If you go ptp and dump the the drive channels on the HRDlx, it wouldn't be bad. The clean channel is actually pretty decent with a tube change. But a 5e3 would be better and more versitile, not a one trick pony. I may just push the shit out of my HRDlx till it goes up in smoke convert it to a 5e3 and save the money on the chassis cabinet. Yeah, that's the ticket........

My HRDv is long gone - it's a HR 5F6A now - threw the 5F6A front end in front of the HRDv power supply and it's a little bit on the hard side but sounds better than anything that's been built in the last 10 yrs around these parts - I accidentaly blew the sag resistor I put in it to keep the grid voltages down (a short story - literally...) and had to bypass it and throw the old GT's back in for a gig on Sunday night - a bit more strident than it was with said resistor and a tad louder and brighter but... the deal is I'm thinkin' of building a 5E3 with Kap'n's mods a la this thread and was wondrin' if JJ 7591's would be a good sub for 6L6GB's...

[stratcat55]

Anyone ever build a 5e3 around a 15" speaker as a combo?

[yankeerob]

That'd be an interesting project - I'd imagine it'd have to be a pretty compliant cone and low power rating to work but I knew a guy with a MusicMan 65W combo with a 15 in it and he got some great vintage-like sounds out of it - mind you by today's standards it probably is vintage by now

[stratcat55]

You guys always get me thinking about amps and playing regularly again. I'm kind of retired from the bigger stuff because of family commitments. I just do an occasional club here as a guest performer and pretty much for fun. I have a friend who plays harp who is trying to get me out of retirement to form another blues band and gig on a regular basis. I'm really getting the itch.
A 5e3 will be mine in the near future.

[yankeerob]

I was fully pro working all over Europe with a show band - got married - quit playing the pro circuit for 11 yrs - got divorced - had a long standing relationship who forbade me to even think about it - was holed up in my loft conversion with a ton of recording gear - got turfed out for being boring after 3 yrs - now been with my current squeeze for 3 yrs and have gotten back out there - I rent a workshop in a mill down the road so I can tinker to hearts delight... I get the occasional stuff but if it's in your blood it'll only come out again or you'll wish you'd let it somewhere down the line...

[stratcat55]

No woman problems here. I've been divorced once, raised a son with the woman I've been living with for over 20 years. She supports me in everything I do. She puts up with a lot. I consider myself real lucky. She's one in a million and every days like a date with her.I was a professional musician, became a professional photographer/artist and student at 50, and now I'm getting the itch again. I'm 52 going on 53, but I refuse to grow up. When you grow up, you get old and die.

[yankeerob]

Erm - yer - that's the truth - on many counts - if you've been playin' that long it takes major surgery to get rid of the itch...

I heard a real deal '57 5E3 a coupla weeks ago and it's inprinted on my mind - Weber do a 'Proluxe' kit that's basically a 40W 5E3 by all accounts - I don't think it would take too much bother to marry the 5E3 front end to the HRDx power section though the other things to consider are you'd probably want a Copper Cap in it instead of a FWBR and I'm sure NTBG or JAM could figure out a fixed/cathode bias switch to have the option - Kap'n published a nice little modded schematic for the 5E3 with 6L6GB's in it - that's a kind of halfway house - in power terms anyway... he's using a tube rectifier in his and reports good results - lots of ways to skin this cat

[NTBluesGuitar]

Weber do a 'Proluxe' kit that's basically a 40W 5E3 by all accounts - I don't think it would take too much bother to marry the 5E3 front end to the HRDx power section though the other things to consider are you'd probably want a Copper Cap in it instead of a FWBR and I'm sure NTBG or JAM could figure out a fixed/cathode bias switch to have the option.

The Weber Proluxe kit is almost identical to the original 5E5, which is the 5E3 40W version: http://www.ampwares.com/ffg/schem/pro_5e5_layout.gif

I have a layout of the HRDlx to 5E5A with the fixed-cathode bias switch that can be used with either circuit. The switching circuit is designed around the HRD bias taps, so any application that re-uses the HRD PT could include the switch:



I once toyed with a 5E5 (not 5E5A) circuit layout for a HRD conversion and have a drawing of it, too.

[stratcat55]

Is there anything in between Tweed wise? I ready to break into my friends house and steal his but he would figure out I took it in a nano second. The sound of a 5e3 is like a drug to me.

[ziess]

Inbetween a 5E3 and a Pro? Maybe an early Tremolux (5E9).

[yankeerob]

Is there anything in between Tweed wise? I ready to break into my friends house and steal his but he would figure out I took it in a nano second. The sound of a 5e3 is like a drug to me.

Having heard that drug I know how addictive it can be - I think you'd have to go with a straight 5E3 if that's really what you're after...

Kap'n's modded 5E3 circuit is a kind of in between but you wouldn't get the same result with HRDx iron as you'd have to go with a different PT to get a 5E3's tube rectifier mojo (the HR PT hasn't got a 5V tap) though you could go for a copper cap to get the lower voltages required - but then the other thing you're gonna find is that the primary on the HRDx OT (4.25K) is closer to the 4K on the 35-40W Pro OT than it is the 5.6K on a Tweed Deluxe... unless I've got it wrong - and please correct me if I have - Kap'n's modded 5E3 is 'squeezing' a little more power through the 25W Weber Deluxe OT than it was designed for... like he says if it goes then it's only $26 down the drain but it's something I'd like to try as I have a little 1W amp I've built from this - I've modded it a little bit to get the sound I want out of it and beefed up the power supply a little but it works on a vaguely similar principle - it's got an 8K 1W OT being fed by a 6SN7 dual triode in push/pull for it's output tube (could get as much as 2.5W out of it though it's being 'held back' by the 1W OT - it - like Kap'n 25W Weber OT - doesn't show any signs of going home as it is built to my spec by a company called Majestic Transformers who by and large build some really top stuff) - the result is a very spongey output with tons of dynamics - not a lot of clean headroom unless you tone it down with 12AT7's but for me it loses the absolutely addictive ballsy natural overdrive and sustain it has with 12AX7's. It will do 1.1W RMS clean but it's a hell of a lot more fun cranking it!... Sounds a lot more natural than a Tiny Terror or MiniMat as both of those amps rely on overdrive in the preamp stage whereas this thing specifically designed to overdrive the 6SN7... it works a treat!

I think what this all boils down to is the logical build with the HR chassis and iron is a HR 5E5 a la NTBG - I like the idea of a fixed/cathode bias option too so it'll still be a nice tweed-y sounding amp - but to get exactly what you're after - if it's a 5E3 - IMO you're gonna have to shelf the HR iron for another project and go 5E3 all the way... My plan is to build a straight 5E3 and a Kap'n model through the summer as a little R&D exercise...

[NTBluesGuitar]

The HRD iron is just way to beefy for a traditional 5E3 sound, IMO. It would be great in a 5E5, and it IS great in a 5E5A.

There is a lack of sag and compression in the 5E5A compared to the 5E3, so if you must have that 5E3 sound, you should get the proper iron and tubes to do so. I just don't see a 5E3 happening with the HRD iron as it is.

Just my pair o' pennies.

[stratcat55]

Yep, without a doubt. If I get this new job I'm after, I may go with a Mission 5e3. The whole kit with a cab. I hear the documentation is really good with Mission and they supply decent hardware. I've played through them and was impressed. I may go with a more efficient speaker. If I do well building it, it's on to bigger and better things and thats where my HRDlx comes in.

[yankeerob]

You may want to consider a NTBG turret board and pick and mix your cab, chassis, iron and spkrs from others - you don't need great documentation to build a 5E3 - it's an extremely basic (and effective) circuit - I think the Mission kits are slightly more expensive than they need to be and TJ's boards are superb - inspired me to build my own and I have to say they're better than any tag or eyelet boards and will be around a lot longer... and from what I can gather - Ted's iron isn't too bad these days - he'd gotten a bit of a rep for some dodgy stuff but seems to have tightened up his QC - if you wanted to spend some extra money you could push the boat out and get MM iron for it - having had a look at their prices they are excellent VFM - in terms of components - they're all available off the shelf but I'm sure TJ'd sort you out a kit of resistors and caps to go with his board for a nominal fee... chassis and cabs are fairly easily obtained from a variety of sources - it's just a thought - but if your heart's set on a Misson kit then so be it...

[JAM]

One thing about a Mission - you're getting the support from Bruce Collins, who can help out with any problems and any mods you want.

[CJ Neel]

There is a lack of sag and compression in the 5E5A compared to the 5E3, so if you must have that 5E3 sound, you should get the proper iron and tubes to do so.

Sag in the 5e3 comes from the PT (depends on the vA of the tranny), the rectifier, the voltages that go to the preamp section (see the Kap'n mods), and most important, the cathode biased 6V6's. The iron should be OK for a 5e3 type build, just not optimum...

[Kap'n]

.

[Kap'n]

Sag in the 5e3 comes from the PT (depends on the vA of the tranny), the rectifier, the voltages that go to the preamp section (see the Kap'n mods), and most important, the cathode biased 6V6's. The iron should be OK for a 5e3 type build, just not optimum...

Yep. In my experience most of the 'squash' comes from the 5K resistor between the plates and screens. When the output section gets pushed hard, the screens dissapate more current, and the voltage drops, choking the output. You can really fine-tune the whole response of the amp by messing with that resistor. I ended up going with a value in the 2.5K range.

Thought for the day: I wonder what would happen if you reduced the value of that resistor, but added a screen resistor on one side of the push-pull? The side would matter, because a 5E3 asymmetrically clips when it's pushed hard anyway. Hmmmm

[CJ Neel]

A trimpot (that could take the heat) would make it kind of dial-in-able...The screen resistor idea is interesting too...

[Kap'n]

A trimpot (that could take the heat) would make it kind of dial-in-able...The screen resistor idea is interesting too...

A great application for a decade resistance box.

The nuances of a seemingly simple circuit are pretty complex.

[JAM]

Yep. In my experience most of the 'squash' comes from the 5K resistor between the plates and screens. When the output section gets pushed hard, the screens dissapate more current, and the voltage drops, choking the output. You can really fine-tune the whole response of the amp by messing with that resistor. I ended up going with a value in the 2.5K range.

Thought for the day: I wonder what would happen if you reduced the value of that resistor, but added a screen resistor on one side of the push-pull? The side would matter, because a 5E3 asymmetrically clips when it's pushed hard anyway. Hmmmm

Somewhere I saw a diagram for a diode string (zeners or something) to keep the screen voltage consistent (kind of like a regulated screen supply), since plate current is affected by screen voltage, putting the diodes on just one side might give some asymmetry.

[Kap'n]

Somewhere I saw a diagram for a diode string (zeners or something) to keep the screen voltage consistent (kind of like a regulated screen supply), since plate current is affected by screen voltage, putting the diodes on just one side might give some asymmetry.

A completely consistant screen voltage isn't necessarily a good idea, because screens have relatively low dissapation ratings. A screen resistor is designed to limit the current, so they don't burn up.

I've also tossed around the idea of zeners and a trimpot in the cathode circuit for a quasi-fixed bias without increasing the cathode to plate potential difference.

[NTBluesGuitar]

The iron should be OK for a 5e3 type build, just not optimum...

That's what I was sayin.

Or at least TRYIN' to say.

P.S. I see you dropped the Ukelele in favor of a Strat?