High gain mod for a HR Devilli

[ICANSEEYOU7687]

Well I just love the cleans and reverb on my amp, but im definaltely more of a hard rock and metal kind of guy. But after having this amp for a while im not to happy with the drive/more drive channel....

I was wondering if anyone has done, or knows of, and kind of mods that makes their gain sound better...

I have a metal muff pedal, and I love it, for metal, I would really like to get my devilles gain better, and maybe even get an overdrive pedal for it for that tube amp gain sound...

Just curious if there was anything out there, I did do a quick search and didnt find anything. But also while im pretty good at soldering, I dont have much experience with reading schematics...

but any help would be appreciated

[TELEPICKER]

You need to swap the tube in V2 position for a 12AT7 or 12AY7.
The 12AT7 is around 60% of the gain of a 12AX7 and the 12AY7 has around 70%gain. Either of these will tame the drive channel. You should also swap the Master Volume pot. Fender used a Linear taper pot to give the impression that this amp is really loud at low settings. The pot should be an Audio taper. Swapping that will give you more control over your drive/more drive channels.
There are a number of other mods which will make a significant difference to the amp. These can be found on Justin Holtons Web Site.

[visa]

i use a sans amp GT 2 infront of my hot rod's clean channel to achieve some really nasty scooped mid OD.

[Ramon Miller]

I seem to have the same problem. If the Drive pot is set at anything higher than 2 on the Drive Channel, the associated buzz is maddening and the More Drive Channel is effectively unuseable because of the hiss/buzz. Does Fender have a better mod than having to change V2 and V3 to 12AT7s and change the Master Volume pot to an audio taper? My DeVille was made in Corona. Is there any difference between this version and the Mexican models?

[²Thom]

Hi ICANSEEYOU7687,

changing the tubes makes a big difference, But I do not fully agree with Telepicker to put a 12AT7 (ECC81) in V2. Its a high-frequency-tube with a not so nice distortion. I 'd rather plug it in V1. 12AY7 may be better.

Try out some JJ's :
one ECC81 (12AT7)
one ECC83S (12AX7)
one ECC803S (12AX7) long Plate more Bass more Highs

Beware of high voltages!

I think you are missing the fundamental Bass in the Drive-Channel. Try 22nF in series to a 250K Trimm-Pot between (-) chassi and R45 the side that is nearer to R73.
And: bias a little bit higer than they do at Fender. For Deville I would say 70-75mV at the Test-Point (85mV schould be the absolut maximum for 5881). Try how You like it. The hotter You bias them, the shorter the Tubes will last but better sound. ..its better to burn out than to fade away... (neil young)

[stratcat55]

You can always give Bob a call ay Eurotubes. The guy is extremely knowledgeable.

[yankeerob]

Listen up guys - done loads of mods to this amp - now I'm fighting the rot - mine's made in Corona as well and I've heard people dissing the Mexican made ones but to be honest I don't think it means a jot - they're made from the same crap boards & components in both places. I am a very experienced bench wireman and engineer and no matter how careful you are with these boards - because the legs of the components are bent before soldering they are a b*tch to remove without lifting pads and damaging tracks. There's hardly any damned copper on these boards so consider yourself warned - modding then is frought with dispair and mine's just back from the second trip to an engineer friend of mine with lab quality tone generator, dummy load and 'scope to see where we've lost the signal this time..

I too like the clean sound - and after upgrading all the power supply caps and a few key resistors around them (C31, C32, C33, C34, C35, C36, R70, R71, R72, R73), upgrading the PI caps (C24, C25, C26, C27), a few others (C2, C5, C6, C10) and finally changing C23 out for a 22nF OD (though I don't think this has anything to do with the clean sound) I have more clean headroom - when it works... seems I now have to whip it to bits again and investigate the path between the wiper on the vol control pot and the other side of K1 (the channel relay) and suspect it might have something to do with my having changed C23...

The point is - if you're gonna get into this modding malarky - be prepared to repair tracks etc because no matter how careful you are it's gonna happen. The mods do - however - actually work very well and once you get the damned thing settled back down and working properly again it executes the Fender clean sound very accurately.

Having said that I already have it in my mind to build a point to point kit (or two) to replace it (as predicted by those who've read some of my posts). One for clean - one for drive because I too am not enamored with it's drive sound - though changing the master pot from 100K lin to 250K log - cranking it up to say 9 or 10 and then controlling the vol of the drive channel with the drive control (or somewhere in between) might be a better way of using it. The thing to remember is that it's a Fender tone stack and the midrange is centered around 300hz (to the best of my knowledge) - not ideal for a classic metal sound.

It's on that basis that I don't think you'll ever mod this amp into being a 'metal' amp - certainly not by swapping tubes anyway. By all means try different tubes in it to see what the effect of swapping tubes is for your own reference but I seriously doubt it'll have the desired effect. I'd say a pedal is gonna be the answer - something that's going to give you the overdrive and high mids/treble that the Deville doesn't produce in comparison to the bottom end it already has. Or use the Deville for clean and get another amp for the metal sound. I know it sounds flippant to say 'just go buy another amp' but... modding that thing to do metal and the clean sound you already enjoy is gonna be way too complicated to be feasible.

[ICANSEEYOU7687]

I agree with you I wouldnt expect to turn this amp into a metal amp. But I would like to be able to reach AC/DC OD levels, or maybe van halen, not talkin about pantera or trivium extremes.

The best I can do for that is to leave it on the clean channel and use my metal muff which doesnt sound too bad. Im just looking for easy mods that take maybe a lil bit of solder and are easy to find.'

Like i said before unfortunately im not to good at reading schematics

[yankeerob]

Try backing off on the drive and use the bright switch on - that's how I use mine - I set the bass at about 4, mid around 4-5 treble and presence up at around 7 - the mid just brings more bass than mid anyway - I crank the master and bring the drive up until I've got a passable overdrive...

I swapped out the stock speakers for Celestion G12T-100's but I wanted to retain a basically American sound and they were a good cheap solution for me here in Blighty - so something in an Eminence is gonna be less expensive for you - I wouldn't wander too far down the 'British sound' road though - That clean sound is still a good tool and you'll start losing it if you go too 'British' with your choice of speakers - the stock speakers are neither here nor there - however - and you'd do well to find something better

The two examples you've given derive(d) their sound from a Marshall/Celestion combination... that's something to bear in mind in your quest for tone - a lot of Angus/Malcolm's tone comes from the power section - in fact Malcolm used a miked up Marshall Club & Country combo (no overdrive) tipped back on the side of the drum riser to get his live sound - the wall of 4x12's was just for show - Angus used 50w plexi's in the beginning and went onto overdrive heads later but still kept his pre-gain further down than you might imagine... Eddie's old set-up was a straight Marshall 100W top with a load of mods and variac trickery - at some point the output of said amp was driving a load of power amps which in turn drove the speakers - 'spose he got fed up with all of that tomfoolery and got himself a Peavey endorsement but never got the sound he'd become famous for again...

Keeping the master up and the drive down will allow you to bring the sound of the power tubes into the equation - have a mess around and see what you come up with - I suppose it also depends on the level that you're playing at as well... Oh yeah - the one mod that you should have done by someone who is handy with a soldering iron is the master pot. I'll have a look see if I can find a source for the part but it's the same pot as the volume control - changing that out will allow you a lot more control at the beginning and the end of it's travel - right now it pretty much just comes straight on - yeah? Swapping it out for a 250K audio pot will stop that happening

[yankeerob]

Fender pot - http://www.tubesandmore.com - wait for the brand logo's to load on the home page - click on Fender and go to page 10 - it's part no. R-VHD-250KA - good luck

[TELEPICKER]

[QUOTE=
after upgrading all the power supply caps and a few key resistors around them (C31, C32, C33, C34, C35, C36, R70, R71, R72, R73), upgrading the PI caps (C24, C25, C26, C27), a few others (C2, C5, C6, C10) and finally changing C23 out for a 22nF OD (though I don't think this has anything to do with the clean sound) I have more clean headroom .[/QUOTE]

Hi Yankeerob. Can you give more info on the reasons for upgrading these components and why. I have upgraded a few with OD's but I have not swapped the Power Supply caps. Does it make much difference? How do you think a Celestion Gold would sound in my Hot Rod Deluxe?

Pete

[yankeerob]

Hmm - well - the caps looked a bit weeny for a 60W amp and it's about 9 yrs old and sounded a bit saggy - especially when you got it up a bit - now it has a very firm response when you play punchy Cropper type rhythm licks - just tightens up the response and gives your output section in particular more current in reserve but there's no real tone change - that came with all the other caps...

Celestion Gold looks a nice speaker in terms of it's published response curve - nice flat response - usual dip at 1.5K but not as steep as a lot of Emi's and Jensens - I suppose that's one reason why I like the G12T - that and the higher resonant frequency (86hz) - I think it suits the voicing of the amp better. You may find the Gold's resonant frequency of 75hz a bit honky - I do - but then again you might find it perfectly livable - that's the crack about this speaker malarky - it's very subjective. I just happen to have struck a happy and economical medium with the Hot 100. I use a total of 4 with the extension cab and the Dv drives 'em no problem with nice even breakup.

I'd also be a bit wary of pushing a 50W speaker with a 40W HRDx - they probably chuck out 50W in reality - 50 filthy watts but 50W nonetheless - one minute you're - the next you're buzz, rattle

[NTBluesGuitar]

Can you give more info on the reasons for upgrading these components and why. I have upgraded a few with OD's but I have not swapped the Power Supply caps. Does it make much difference?

Power Supply caps just plain lose their performance over time as they age. It's a maintenance thing.

When you're messing with Power Supply caps, changing values significantly actually makes the difference. Going from 22uF to 30uF doesn't do much, but going from 22uF to 47uF may.

Hmm - well - the caps looked a bit weeny for a 60W amp and it's about 9 yrs old and sounded a bit saggy -

BTW, the only reason Sprague Atoms seem 'beefier' is that they are manufactured as 'direct replacement' to meet size specs for older hardware that requires size. They're really just tiny caps in a big tube. They charge so much more because their manufacture is deemed obsolete now, and maintaining the product isn't economically viable anymore.

I use Xicon electrolytics instead.



The only size that really matters is the operating spec numbers (uF and Voltage).

[yankeerob]

Well I'll be danged!

I've used some TAD badge-ups called 'Gold Caps' - no idea who makes 'em but they're a lot cheaper than importing Spragues but seem to vary quite a lot - all on the plus side but the two 100uF's measured 120 & 135, the 47uF's were 49 & 55 and the 33uF's (close as I could get to 22uF) were 35 & 36... I used a pretty decent meter (Fluke Model 12 - it's not mega but it's better than your average Radio Shack DMM) Would these +variances cause the higher voltages mentioned later?

Have discovered a cheaper source for Philips type polyester 630V caps (that TAD call 'Mustard Caps' and charge way too much for) - they're Vishay MKT1813's, look identical (prob because they are) and sound pretty good... (been pricing up bits for a Weber 6O100 clone - might just build the whole damn thing from scratch apart from the obvious things like PT's, OT's, etc. - you said it would happen - probably do a 5A40 after that)

Back to my ailing Dv - the prob I'm having is somewhere between the wiper on the vol pot and pin 7 on V1(B) and as I can't get at the solder side of the board when it's powered up (like I've had time to build a jig or the money to splash out on a spare PT, choke, OT, and dummy load, geez!) I'm a bit in the dark. We (my ex-BBC engineer friend John who has loadsa cool ex-BBC test kit & I) traced a test tone with a scope from the input through to the wiper but it doesn't arrive at pin 7 and there's not a hell of a lot in between (the circuit's identical to the Dx - input-> V1A -> vol pot -> relay -> 10K resistor -> V1B) the weird part is when the board's out I get a 10K DC resistance between the wiper and pin 7 so the relays passing voltage through it when the board's out of chassis but the circuit is interrupted somehow when it's in and powered up...

Other things of note -all the supply voltages we've checked (B+, X, Y & Z) seem fine if a tad higher than spec - maybe 20 or so volts higher than what's on the drawing but I figure it's just idling so it's no big thing, right? The board's been in and out that many times that the danged heater supply wires between V1 & V2 finally frayed & broke so I've replaced that now

I can only surmise that K1's given up the ghost in some way - unless somethings wrong with the control voltage which is causing it to break but not quite make when it's powered up? You can hear a switching noise when you press the channel switch in and out but nothing's coming out of either channel - it's driving me bonkers as it seems to be something so damned simple and the amp sounded great until this latest drama

[NTBluesGuitar]

Have discovered a cheaper source for Philips type polyester 630V caps (that TAD call 'Mustard Caps' and charge way too much for) - they're Vishay MKT1813's, look identical (prob because they are) and sound pretty good...

I stick with Mallory 150s. But then, Mouser is just on the other side of DFW from me, so I can get stuff fast.

I keep forgetting you're on the other side of the pond and parts choices are different for you, but Spragues aren't worth the cost locally either, IMO. Not that they're bad in any way, just not necessary.