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Well, they arrived today...a lovely set of turret boards from our good friend Yankee Rob....Thanks Rob, lovely job. He also supplied a very professional CAD drawing of the layout.
This will be a 5F6-A with a buffered Send/Return circuit. I can't wait to get started. I've already prepared the chassis as much as I can without the boards, now the fun starts. Got a gig tonight but the rest of the weekend free to make progress.
Pete
Awesome! These are fun to do. I'm actually finishing one up for a buddy now.
I had a tech redo my amp but all we did is change the caps to accept vintage GE 6l6 tubes and add switchcraft jacks on the input side.my greenie has stock 8 ohm celestion. It sounds incredible now. What does your board upgrade do?
JMO, of course, but I cant see why you'd ever want to put a send/return in a 5F6-A (or any tweed amp). The beauty of the tweed circuits is their simplicity, and I believe for tube amps in general, the simpler circuits sound better. Unless your buffered circuit is completely neutral (or bypassed), it could color the sound. I've been enjoying my 5F6-A clone just going straight in, no pedals. It sounds incredible.Quote:
Originally Posted by TONESEEKER
Awesome Pete! I just got your emails.
I'll need to pop along to one of your gigs to hear it when you've got it done.
If you're missing any hard to get caps (or don't want to pay £2 for a single one from Maplin) give me a bell. I've got a complete set of spare caps and resistors for a Bassman that you're welcome to dig into.
Good luck!
Tommy.
Not really a board upgrade, but a total gut and rebuild of the amp re-using the transformers and all.Quote:
Originally Posted by JM3
Rob's design looks a little somethin' like this:
http://images.lilypix.com/albums/use...A_03_25%25.jpg
:D
By JAMI just got so used to boosting the tone of my HRDx by using a SANSAMP GT2 in the effects loop. I didn't want to be without an fx loop. I know everyone says I won't need it and I did consider that it might color the tone. I expressed that in an email to Rob. That's why this one will have a switch that completely bypasses the circuit when it's not in use.Quote:
Unless your buffered circuit is completely neutral (or bypassed), it could color the sound.
Thanks for the offer Tommy. I bought most components in bulk with the intention of doing another project after this one. Still, there may be something I'm missing.
Pete
Apart from it looks like this now- the previous photo was the mk1 version - I'd reworked the power supply so much I wasn't happy with the mess around the turrets so I built a new PS board (hence the new modular approach to these) and sawed off the old bit... there's a huge choke on the other side of the chassis as well as a 100ohm 25W resistor in between the FWBR and the first cap...
http://images.lilypix.com/albums/use.../HR_5F6A-2.jpg
Made room for the extra caps by moving the FWBR to the bottom left hand corner and the feedback loop isn't like this anymore either - ah... progress Jim but not as we know it...
I wouldn't mind having another go at putting the S/R back in as it's already drilled out for it but it's a real volatile area to be messing around... my advice is to get the amp working and then try putting it in circuit - you can just pull the tube for now and leave the heaters wired up but I'd definitely get the basic amp off the ground first... having too many things in the mix can send you round in circles if you have problems... then to power it up you'd just need to put a link in from the positive side of the last filter cap to the power in on the FX board and pop the tube back in :D
I'll have to have my tech look at this as this is more his speed
Completely simplifies the amp - and also makes it far more repairable... mine actually runs cooler - sure it still gets nice and toasty (and I make a habit of getting to the gig in plenty of time to get 'er nice and warm before we start and allow plenty of time for 'er to cool down before transporting) but it doesn't run nearly as hot as it did when it was a stock Dv... but as JAM says - it's a good solid basic circuit that has it's own mojo - if you use the Drive channel a lot then this wouldn't be the amp for you - I used the clean channel far more than the Drive channel - now I get a fab clean sound with far more depth than the old Dv did... if I need dirt the Blackstar HT-Dual DS-2 gives me two extra 'channels' - see http://www.blackstaramps.co.uk/products/ht/htdual.htmlQuote:
Originally Posted by JM3
It's very transparent and is built like a tank!... my only criticism is the 16V AC supply - being a transformer in a standard plastic inline casing with a plug on one end and a standard coax power connector at the other - it's not as road friendly as the main unit :D
Didn't get as much time on the amp this weekend as I had planned. Family demanded my time. However I did make some progress.
http://images.lilypix.com/displayima...bum=2259&pos=5
I will populate the remaining FX Loop board tonight. I have to go away on business this week but next weekend should see some significant progress.
Pete
Good stuff.
Very cool, Pete! My latest conversion got fired up for the first time yesterday with no problems! First time I got a build to work from first power-up.
Now I get to re-cover with tweed. :D
Outstanding mate! What are those blue elctrolytics?
Just ordered a 6A20 (Blackface Deluxe Reverb) myself!
Tommy.
I hope mine fires up without a hitch TJ. I'ts gonna be a scary moment flicking the standby switch for the first time and waiting for the big bang which destroys the transformers and the speaker and my NOS tubes. I'm optimistic really:D
Tommy, the blue caps I got from Farnell. 22Mf 450 volts. The grey ones I savaged from the Hot Rod as it was only 14 months old.
My first aim is to get it working without the FX circuit. I'll bring that in later only after I'm satisfied with the raw 5F6-A.]
Pete
The IC's should do you OK for a while yet - besides - the ones I've gotten from Rapid seem pretty damned good (and inexpensive) if the IC's let you down...
I've got a Sprague 25uF 100V that I got from Mouser and an axial 100uF 100V from either Farnell or Rapid that'd be a better fit for those caps in the bias - I had a look at the earthing scheme on my clone - the first two filter stages are star earthed individually back to the same point as the 1ohm's from the cathodes (just behind the sockets) and the third and fourth are anchored up in between the mid and presence pots...
You can keep your OD's... those VR mustard caps are the dog's - they really are... :D
Thank's Rob,
I'm working down in the Midlands for the next few days so I wont get a chance to update this thread till Friday.
Pete
Triple-check your work and you should be fine! I think the biggest problems you'd have is a bad ground, bad solder joint, etc. and there would be some noise, or no noise.Quote:
Originally Posted by TONESEEKER
I checked all my ground points before I fired it up. Then I left it on standby for awhile watching the tubes carefully as they warmed up.
I'd never fire up an amp for the first time with tubes in it. After triple-checking the wiring I:Quote:
Originally Posted by NTBluesGuitar
- Fire it up without any tubes, and check voltages on the rectifier socket.
- Install the rectifier, fire it up again, and check the voltages on all the tube pins.
- Set the bias to maximum negative voltage
- Install the power tubes and bias them.
- Add the preamp tubes, and see what happens.
A cock up that cost me a pr of good JJ's was putting the diode in the wrong way on the bias - as interesting as it was to find out what a melting envelope looks like... I'm not in a hurry to do it again...
Have had a good look at what you've done so far and everything's in the right place as far as I can see... :D
You are going to love this over the HRD, I have a 5F6a that I built and it's the best sounding amp I've built. By the way I used the OD's and I think they are great for Fender Amps.
Kap'n mentions some steps that I left out in my description in my haste.Quote:
Originally Posted by Kap'n
I did most of what he listed, too, FWIW.
You can take your pick really - the VR's (Vishay Roederstein) are a bit more forgiving though... you pays yer money... you takes yer choice :DQuote:
Originally Posted by wingnut1
Hi Guys,
managed to get some internet access so popping in for a few minutes. Some good advice there from Kapn and TJ. I already checked the copper cap and the heaters before I got the turret boards. I will check check and check again before flicking the standby switch on with tubes and speaker attached. This weekend's gonna be inreresting.
Pete
My copper cap was DOA. Before my amp was done, I tried it with another amp, and the fuse blew immediately. A 5U4GB went in and that's what I'm sticking with. (Glass just looks better anyway!)
What B+ are you getting with the CC?
Tommy.
I don't think Pete's got a measurable B+ yet and Joe's using a toob.... :DQuote:
Originally Posted by ziess
I thought he said he checked the CC? I assume he just wired up the rectifier socket and mesuared voltage?
Tommy.
Mine's around 371V in Cathode Bias, and 375V in Fixed Bias with a WV4 Copper Cap.
Orignal HRD B+ is listed at 431V on the schematics.
I'm also interested in seeing what Pete's ends up being.
Hey, it might help if I spelt 'measured' right...
I've found them conservative with export iron... :DQuote:
Originally Posted by NTBluesGuitar
Tommy, I just measured the output from the copper cap without the smoothing capacitors connected, just to make sure it was ok. I didn't have the boards at the time and didn't want to risk 500 volts dangling around the chassis. The output measured 483 volts. I checked the mains supply and that was 240 volts. The stock HRD configuration was for 230 Volts so I changed that to reflect 240 volts.
That reduced the output by 20 volts. Once I get the rest of the circuit configured (hopefully this weekend) that should come down a bit more.
Pete
Having a load in place will affect the B+, so, I bet it changes significantly.
So you're at around 465VDC now? Sounds like it should be fine then.
Mains at my house is 240VAC too so that's probably the best bet for central Scotland.
Good luck with the rest of it!
Tommy.
OK guys - we're cooking with gas - worst case is Pete needs a CC that'll gobble more power - and there are few places in the UK with less than 240V these days...
He's got quite a bit of work to do on it yet - my advice at this point is don't rush it - make it nice and clean but don't get too fussy about dressing your wires - I made that mistake on the Mk1 version - these things are more dynamic in terms of noise with good bottles in 'em... :D
Me bein' a naive Yank...wait, I'm a Southerner now; gave up Yankee status...doesn't the export iron convert your wall voltage to the amp's usable voltage?Quote:
Originally Posted by yankeerob
Anyway, that number will change with the amp's load on it. Best to test that number after the circuitry is added, THEN look at a different CC *cough*IuseWV4coppercapsinHRDlxrebuilds*cough*.
:D
Hey Teej - I was merely pointing out that I think the Fender schematics are based on US iron - it's been my experience that even before ripping out the old board, with the PT set for 240 and under load that the voltages were higher than spec...
Having said that Pete's got a WZ34 (I think) which should still provide a decent enough drop under load - I think my voltage was 491 after the WW resistor straight off the rectifier so he seems to be in the right ballpark - I wound up with the grids and plates at nearly bang on 450 by the time it was biased up properly - I reckon he'll be just under that if he's starting at 483... he may need - however to adjust his bias range resistors to give him enough to hold the 6L6's down to 28W at idle.... that remains to be seen...
Hence my saying worst case is that he'd need to go to a WV4 though I really don't think that'll be necessary... I think those voltages on the schematic are fart gas anyway - it's what you get out of the OT that counts at the end of the day :D
I wasn't trying to stir up a wasps' nest, my friend. 'S'all goof!
I really am naive about the export voltages and wanted clarification on my assumptions.
One detail I will bring up again is that Pete's PT is the Deluxe, and you have a Deville. I've never worked with a Deville, so I'm not sure how close they are, but due to your generous documentation, I know the bias setup is different.
One detail I didn't consider is that he's using a 5F6A circuit which likes a higher B+ anyway, so the WZ34 won't drop it as much as the WV4 I use for the 5E5A.
Hey dude - no worries - I think he's gonna be in pretty good shape when there's a load on - my voltages dropped considerably when I started dropping the bias plus the interaction of the CC as opposed to a straight FWBR is gonna be interesting - we have a Dx in the workshop awaiting a replacement OT (ordered three weeks ago now) - I was hoping the guy would sell it for scrap so I could do a tandem project but... :D
Hi Guys,
alas I didn't get the time I wanted this weekend. It was her :wife: birthday, but I managed a few hours on Sunday. Got the pots wired up and sorted out the 3 star grounding. Just didn't get to the point where I could supply some electrons and get a measure on the voltages. Hope to have more progress this week.
Pete