Latest Lil' Screamer

[yankeerob]

Finally got around to putting together the 'Kap'n' 5E3 project - nice one Kap - just fits's in standard 5E3 size chassis (undrilled) - it's doin' 21W just before clipping - may put channel combining switch - tried loads of different 6L6's but got max power out of some old Shuguang coke bottles (they're not GC's as printed on the envelope - closer to Kap's spec of GB's) - tried some mil spec 5881's, a new pr of Winged C GC's, virtually everything I had lying around - can't seem to get my hands on any decent NOS 5AR4's (they're fetching stupid money on fleabay) so I tried new production Sovtek and JJ's - the Sovvies won that argument - tried loads of bottles in V1 - JAN Philips 12AT7 had slightly sweeter top end than a Mullard CV4024 but they were the best out of what I had - a bog standard Tung-Sol 12AX7 in the PI works fine - I've been searching for some nice faceplate material but haven't been able to source the colors I want (brown/cream plastic for engraving) - cabinets are next thing to organise - but yer - this thing does tweed very nicely and sings like a bird...

[Kap'n]

You diggin' the sound? Which circuit did you use?

Man, that's a brutal set of iron!

[yankeerob]

I used the one you posted - 5E3 with a few mods - the iron's from another enthusiast - Duncan Newnham - down in Swansea for any of you UK guys - builds some nice stuff - everything he's sent is built like a tank - we're clubbing together to build the best amps we can between us (he also builds cabs - pine or ply) - it's a funny scene over here - there's an unbelievable amount of bogus 'vintage' Orange and HiWatt stuff that John and I keep getting emails from the States about - combine that with the stuff on this site and I don't need to point any fingers - infer what you like and you'll not be far from the fire - seems to be an accepted practice as I had a conversation with a Stateside dealer 'cause he had some good prices on Mojo stuff as I need some good quality tweed cabs (it's the quality/attention to detail of the covering that's paramount and a lot of guys who do it over here piss and moan about tweed and we only have so many hours in the day ) - I explained what I was doing (building tweed clones) and he said Mojo were building the best cabs for 'serial numbering'... all I could do is rub my chin ruefully for a minute and think to myself - geez everyone must be at it... any road - this thing sounds like the 5E3 I built just a bit louder and maybe a little hotter (kinda makes you go into Billy Gibbons mode circa Rio Grande Mud/Tres Hombres - the clarity of single notes just effortlessly springs out of finger picked chords and I found myself doing Santana licks next - I mean - these things are just the nuts and you don't have to be a genius to build 'em!) - the 47nF coupling cap on the 'normal' ch is a good swap (I think Gris mentioned it in my 5E3 thread so I'd better tell 'im that it does work) and the 5uF cathode cap (instead of 25uF) on V1's a good call in this setup - I haven't tried a 12AY7 in there yet (I've one spare NOS GE that I got from Tube Depot for $20 plus the postage - good bottles...) but I got some JAN Philips 12AT7's at a pretty good price that sound best so far as an alternative - so yer I'm diggin' it alright - humble thanks - I reckon it was just power out of those 6L6's that sent that OT home - Duncan reckons these trannies's are good for 50-60W - we'll see - if they don't stand up we'll just uprate 'em - it's worth it - I mean - that circuit is the juice for anyone who wants high octane swamp

[yankeerob]

Got some mil spec 6n3c's (Svetlana) and stuffed 'em in - sounded great - switched off for the night - next morning ran it up on the bench to see if there was any change in output power - slight drop but it sounded brighter when I tried it - plugged it back in and now I'm getting that horrible 'blat' on punchy chords - hope I haven't fried the OT though it should have been able to take the extra juice - is there anything else I can check? This is the schematic I used...

[yankeerob]

I promised to post the results of my tinkering with this project and have come up with a schematic that works...

OK - it doesn't behave exactly like a 5E3 - a bit more headroom, slightly more top and it takes a little longer to start sagging (note the 47uF filter caps - I quite like it this stiff but I'm sure experimentation here will derive varying results) - but it works, is stable and still goes brown when you crank it - I'm using 6n3c's that we get from the Ukraine and they're surprisingly good - a matched pair of JAN Philips 6L6WGB's sound smoother but I'll reserve final judgement on the 6n3c's as a lot of the Russian mil spec stuff just takes a little while to break in, are very consistent and do tend to last well - we've got an RFT ECC81 (very nice bottle for the money) in V1 and a standard Tung-Sol 12AX7 in the PI - the PT is wound to Weber specs and the OT is 6K6 primary with the 6n3c's quite happily producing 19W RMS into 8Ω - I don't bother with 4 inputs as I've found that if you want to jumper the 'channels' with a mini-toggle it works just fine - just use yer noggin and make sure you defeat the earthing switch on the unused jack input... but yer it works - and very well... next step is to put this circuit in a HRDx conversion (SS rectifier w/sag resistor) - have customer lined up for that in the new year... many thanks to the Kap for getting this one going

[Kap'n]

Very cool. What sort of voltages are you looking at on that one? What's the primary Z on the OT?

I find most of the sag comes from the first dropping resistor, but stiffer caps probably suppress ghost noting as well as stiffening it a bit.

If you want some more high end, another thing you can do is install a -fb loop a la BF Princeton and add a small bypass cap. tweak to taste Still further from tweed territory, but an interesting avenue to explore.

[Offshore Angler]

...
Man, that's a brutal set of iron!

Ya think?!!!

[phantomman]

Definitely looks like a muh-cheen for some serious honkin'!

[yankeerob]

No I can't complain about iron like that - a fella in Swansea winds 'em - practically by hand though he's got the gear to machine wind 'em... they were 20 GBP ea. (though we're now looking at about thirty for them) - we've got 400V B+ - and as stupid as it sounds - I can't get at the plates (adapters need makin' for this sort of situation - I've flipped a 5E3 chassis and have made the board too big... d'oh) the PI's got around 285V plates and everything's happy from there... swapped the power tube cathode resistor from 7W 270 to 11W 330 and changed the V1 cathode cap to 10uF... had a coupla 10's in series for 5uF but 10's fine I reckon... tried an AX7 in V1 - too filthy - though some might like it - the 81's got plenty enough gain and the RFT's a pleasant surprise - for six and a half US too... German bottles with Mullard M's on 'em... any road - we'll figure out how we can mess with it - but's definitely a good platform... cheers fellas!!

[yankeerob]

What's the primary Z on the OT?

6.6K or thereabouts...

I find most of the sag comes from the first dropping resistor, but stiffer caps probably suppress ghost noting as well as stiffening it a bit.

I couldn't put my finger on it but that is - astutely - a major departure from the straight 5E3... well spotted that man...

If you want some more high end, another thing you can do is install a -fb loop a la BF Princeton and add a small bypass cap. tweak to taste Still further from tweed territory, but an interesting avenue to explore.

I'll file that in the drawer marked - 'if a guy's going deaf ' on this one... naw - I reckon this circuit - in terms of how it interacts with what you plug into it - is already as far as I'd want to get away from a straight 5E3 - if anything - it'd do well to have the combining switch to bring some of the bass channel in - which is on the verge of imperative if you stick a Tele in it - it's a dream with PAF's though - really chirpy yet creamy at the same time in the traditional Fender response to HB's - 'spose all I know is that you can mess around with the circuit from this point and you have solid ground to fall back on... nice one Kap!

[gooman]

New to this 5e3 amp topic how does the 1900.00 fender reissue stack up to the kit amps. thanks for replys.....................Gary

[Cygnus X1]

I would think the RI isn't hand wired (turret board).

If you think you're ready, then look into building a kit.
Much more bang for the buck, and the education is priceless.

[NTBluesGuitar]

I would think the RI isn't hand wired (turret board).

If you think you're ready, then look into building a kit.
Much more bang for the buck, and the education is priceless.

You'd be wrong about the RI, Sir Cygnus...



But I wholeheartedly agree with the rest of your statement, sir.

New to this 5e3 amp topic how does the 1900.00 fender reissue stack up to the kit amps. thanks for replys....

Well, I read a lengthy article on how Fender decided on what components went into the Deluxe (iron especially), and, while buying a Fender gets you a unique set of hardware that you can't really get anywhere else, they're built to the original specs as most kits are. However, Fender has to have certain parts engineered in to insure this product passes international regulations, so it will differ from the original Tweed Deluxe in some ways.

You're spending over $1,000 on the fact that it's a true Fender. To some, that's not a problem. To others, it is.

My opinion, and again, I agree with Cygnus, is that you can get more bang for the buck with your own build, even if you do it to the same specs as Fender did with the RI.

[yankeerob]

Hell Teej - he'd definitely get more bang for his buck if you made one for 'im!! I personally wouldn't buy an amp made by FMIC in the modern era - not just 'cause I'd build it myself from now on either - it might even be a pretty decent amp - but that's just way too much bread and 'international requirements' is a poor excuse for hiking up the price - a good amp should supercede all international requirements inherently... a lot of it's to do with electronic emissions but if it's built right in the first place there shouldn't be any problem!

[NTBluesGuitar]

Well, as I said, to some folks, the extra bread for a real Fender is worth it. I understand it although I don't agree with it, personally.

Re-sale value is another topic altogether, though. But I buy 'em to play 'em.

[yankeerob]

I don't know - I reckon Green Eagle's are a good investment - I'm not necessarily talking about HR and Blues series conversions though I'm looking forward to chuckin' this circuit in a HRDx carcass and seeing what we come up with - worst case is we throw in a tube rectifier and an extra 5V tranny to run it but might get away with a SS recto and sag resistor... my point is don't sell yerself short - you build some good stuff

[NTBluesGuitar]

I don't know - I reckon Green Eagle's are a good investment - I'm not necessarily talking about HR and Blues series conversions though I'm looking forward to chuckin' this circuit in a HRDx carcass and seeing what we come up with - worst case is we throw in a tube rectifier and an extra 5V tranny to run it but might get away with a SS recto and sag resistor... my point is don't sell yerself short - you build some good stuff

You're too kind.

Give the Copper Cap a go first if you try the circuit. If you don't like it, you can add the 5V iron and go real tube easy enough.

I'm a fan.

[yankeerob]

It's a lot cheaper to buy some diodes, a 25W resistor and an NTC but I take yer point and that's precisely what I was gonna do - it's for a guy who's tried this amp but has a HRDx... he's totally smitten but won't be able to get the price of a new build past his front office he can afford to have his amp converted after the hols though... we're talkin' a drop of 35-50V or thereabouts - easy-peasy...

[NTBluesGuitar]

Good point. I throw out the Copper Cap as a solution for the Diode-Sag Resistor-Thermistor setup, but as you point out, any combination of those will get the same results. I also forget there's a shipping cost you have to deal with that I don't.

I'm just a fan of that groovy copper tube pretending to be a tube rectifier.

[Cygnus X1]

Thank you for the pic, NT.
I was too lazy to look it up.
I agree the very word "reissue" would drop resale value.

I use diodes (full bridge) in a 4 diode config on a tiny board frequently.
Very cheap and easy to make. It leaves that rectifier socket open, though. Never tried it on the 5E3. But I'm going in the opposite direction. I want less headroom, more breakup. So the 5Y3 stays.

[ziess]

Rob, can you get a hold of these OTs?

[Gris]

Hmmm, I missed this thread. FWIW, I have come to the conclusion that the very best overdrive sounds are a direct result of lower voltages. Dunno how, just what I hear...

[Kap'n]

Hmmm, I missed this thread. FWIW, I have come to the conclusion that the very best overdrive sounds are a direct result of lower voltages. Dunno how, just what I hear...

Classic Marshall preamp design seems to follow this logic as well.