Hello - Newbie here .. Help with Francesca Parts Please

[martins3325]

Hi, Ive been reading here for a while. Just officially registered. Some may recognize my ID from the gear page. I own some high end amps including a Komet Constellation, KF50LTD--just sold--, Clark Beaufort, '55 Deluxe, and a 63 AC30 Supertwin head. Anyway..I always wanted an Express but simply could never afford the real thing, and after seeing Francesca I decided to get a Two Rock Kit and give it a try. I admit I dont know crap about electronics really but I can solder and can mimic what I see, so my plan is to copy as exactly as possible Francesca and let a real amp expert tweek it when its all together. So far im assembling the parts and have tracked down most..but there a few I can not quite make out what they are.
I have a few questions:
1: What wattage resistors should I use? Looks like 1/2w in Francesca..can resistor wattage rating effect tone..would using 1w resistors be detrimental to the end result tone?
2: Would someone be so kind as to tell me what type and value these parts are? --




Thanks..I know im in over my head as far as final assembly goes ..but if I can get the best parts and copy what I see to a Tee then I shouldnt be far off having a pretty close copy once I get a true amp expert to teek it all up. And It might be fun trying to get there. Thanks in advance! Martin

[Mark]

Dear Martin

Use half watt and one watt carbon film resistors.

The resistors that you asked about are Vitreous Enamel 5W Wirewound Resistors. Ken has used the typical sandbox (square white) 5 watt wire wound resistors in the first Liverpool amp Ginger.

Regarding the build take it slow and think it all through and you should be okay. When in doubt ask.

[martins3325]

Thanks Mark. BTW I really like your 6V6 Clip alot! Made me consider going with 6v6's especially since i got a buncha old Black Plate RCAs

Just for clarity, you said:
"Use half watt and one watt carbon film resistors"

On the preamp board the only --what appears to be-- 1 Watt resistor I saw was what looked like one 470 Ohm resistor. Am I correct..i wanna get it right because im planning on using all Riken Ohm resistors which are Very expensive..so I dont want to buy all 1/2watt and find out I got the wrong wattage.

Any ideas on the capacitors i showed pics of?
What is that Bue one?
What value is the ceramic disk one?
And any ideas what those maroon "orange drop" looking ones are.

Im also thinking of using Silver 18ga wire..would this be a good choice you think?

Sorry for the idiot newbie questions..Just wanna get my parts list right. Thanks!!

[Robert]

Martins, welcome aboard. I have as much experience as you however I really didn't have any trouble with the build. Just use the A1a schematic and the TR schematic/layout as well as our pics posted here. Randall Aiken has a great technical article about which wattage resistors to use where. However, his recommendations are for increased safety and overbuilt to an extent I don't see on many other builds. I would recommend using cheap Xicon carbon film resistors to begin with on the preamp board, stick with the TR wattage recommendations for the others, and when you get your values worked out then you could try the expensive Riken resistors. Your cap choices are more important tonally. I doubt you will appreciate any difference tonally though. I would also suggest not being overly particular at the beginning. You will find it is not that hard to voice the amp the way you want. For example, the silver mica bright caps you have pictured may or may not sound correct in your build. You may not even want two choices there. The pF values may not be suited for your guitar, single coils/humbuckers or musical style. You will likely want to alter some cap and resistor values as well. I used 18 gauge solid copper wire because the bends stay in place but it is a bit bulky in the turrets. I doubt electrons care if they are flowing in copper or silver. The real fun and learning is in the experimenting after you get your circuit working. And of course, you will never get your parts list right, at least the first time!

[martins3325]

Thanks for the welcome Robert. Ive decided to go for the gusto on this build because I really dont aspire to be an amp builder so much as I just want a REALLY close Express clone. Ive got most of the parts in francesca deciphered and recieved most already except for the caps I showed in those pictures which I admittedly cant figure out what values and type they are. I got the Mallory TC electrolytics and the Mallory PVC caps as in Francesca. I had a conversation with a rather well prominent amp builder with very strong ties to KF and he told me the Two Rock Ruby Trannies were a great start and to mimic Fran as close as possible and i'll probably end up with a great amp. He wont touch the Ruby Kit because of his ties to KF..which I totally understand--otherwise id of just had him build it-- Like I said im pretty much a complete electronics idiot but I can mimic what I see pretty well usuallly --THANKS to whoever took the Francesca pics--. I figured the Rikens would be good resisters cuz they have such tight tolerences they would probably be closer to where Ken wanted them to be without having to be a mad scientist parts tester like allegedly he was.

[Chris G]

Thanks for the welcome Robert. Ive decided to go for the gusto on this build because I really dont aspire to be an amp builder so much as I just want a REALLY close Express clone. Ive got most of the parts in francesca deciphered and recieved most already except for the caps I showed in those pictures which I admittedly cant figure out what values and type they are. I got the Mallory TC electrolytics and the Mallory PVC caps as in Francesca. I had a conversation with a rather well prominent amp builder with very strong ties to KF and he told me the Two Rock Ruby Trannies were a great start and to mimic Fran as close as possible and i'll probably end up with a great amp. He wont touch the Ruby Kit because of his ties to KF..which I totally understand--otherwise id of just had him build it-- Like I said im pretty much a complete electronics idiot but I can mimic what I see pretty well usuallly --THANKS to whoever took the Francesca pics--. I figured the Rikens would be good resisters cuz they have such tight tolerences they would probably be closer to where Ken wanted them to be without having to be a mad scientist parts tester like allegedly he was.

Hi Martin,
Those caps on the switch are poly or Mica types,one is 500 pf the other is a lower value.......different level's of brightness.

the cap across the switch is a m.o.v.

The last cap is eaither a ceramic or poly 47pf there to remove some high end.

Martin,can you read a schematic? I would spend some time trying to learn how to read one if you can't.There is a lot more to building an amp than following a picture.......I'm not trying to be an ass**** but there are deadly voltages contained in every tube amp!!!!!

If you have questions ask them before you hurt yourself or your build.

You could also have your friend that builds amps just check your work before you throw the switch!!!!

And last but not least.......have some fun!!!!!!!!!!!!!!

Thanks
Chris

[martins3325]

Thanks for the parts ID Chris. Advice is well taken..im not so arrogant --nor do I want to demean this art-- as to think I can do this 100% by myself by copying a picture. I just want to get it 95% there then hand it off to an expert. I certainly wont be flicking any switches before a true expert goes over what Ive done. I think it will be a sense of satisfaction if I can get it mostly there though. Thanks again!

[Chris G]

Thanks for the parts ID Chris. Advice is well taken..im not so arrogant --nor do I want to demean this art-- as to think I can do this 100% by myself by copying a picture. I just want to get it 95% there then hand it off to an expert. I certainly wont be flicking any switches before a true expert goes over what Ive done. I think it will be a sense of satisfaction if I can get it mostly there though. Thanks again!

Hi Martin,
I re-read my post........those 2 caps on the switch are mica's not mylars.....You are right on about the satisfaction.......nothing like takeing a bunch of metal,plastic,wood and glass and being able to make music out of it!!!!!
Chris

[UR12]

Martin

The two green resistors are 1k 5watt......The two caps on the switch are 500pf and 100pf (some schematics show a 500pf and a 10 pf).... and then of course the M.O.V and as ChrisG mentioned the blue cap is a 47pf.

Welcome to the board and good luck with your build!

[Chad]

Not to jump into someones thread, but the cap on the power switch is called a M.O.V? (METAL OXIDE VARISTORS ?)I read a little about it from what I understand is that just some kind of surge protector or not ??
Sorry about the lack of knowledge I have, but I never seen (or used) one before untill I seen those pics of Francesca. Should I use one on my build? Thanks , Chad

[martins3325]

Thanks for the help guys. Got my Francesca shopping list almost done..heres what I have. Maybe will help someone else..if you see errors please let me know. Am i correct that Francesca uses 1/2watt resistors almost exclusively? --except for what appears to be the 470ohm one--


QTY Part
3 Piece - 20uf 450V Mallory Electrolytic Part: TC75
3 Piece - 40uf 450V Mallory Electrolytic Part: TC78
2 Piece - 22uf 25V Rubycon Electrolytic (Bought Mepco from Torres)
2 Piece - 10uf 100V Rubycon Electrolytic (Bought Sprague 10uf 150V)
3 Piece - .022uf 630v Mallory 418P or PVC6122 Orange Drop
1 Piece - .0022uf 630V Mallory 418P or PVC6222 Orange Drop
2 Piece - .1 630v Mallory PVC601 Orange Drop
2 Piece - .047 630v Mallory PVC6147 Orange Drop

Tube Sockets
3 - 12ax7 - Angela Premium Ceramic Silver
2 - EL34 - Yamamoto Premium Teflon

Perforated Turret Board : www.turretboards.com

Pots:
3 -PEC 1 Meg Log Taper
2 -PEC 25k Lin Taper
1 -PEC 250k LinTaper
1 -PEC 5K Lin Taper

Power Supply Caps/Resistors
1 - 220k Carbon Film - 1/2 Watt Riken Ohm
1 - 15K Carbon Film - 1/2 Watt Riken Ohm
1 - 47K Carbon Comp - 1/2 Watt Riken Ohm
4 - 9.1K Metal Oxide - Xicon 3 watt
5 - Diodes 1N4007 - Mouser P/N: 833-1N4007
1 - Cement power resistor Xicon 1-Kohm 25W

Preamp Resistors
1 - 1.5K - Carbon Film 1/2 Watt Riken Ohm
5 - 100K - Carbon Film 1/2 Watt Riken Ohm
1 - 150K - Carbon Film 1/2 Watt Riken Ohm
1 - 2.7K - Carbon Film 1/2 Watt Riken Ohm
2 - 10K - Carbon Film 1/2 Watt Riken Ohm
2 - 1Meg - Carbon Film - 1/2 Watt Riken Ohm
1 - 470 ohm Carbon Film (not 470K) - 1 Watt Riken Ohm
1 - 82K - Carbon Film 1/2 Watt Riken Ohm
2 - 220K - Carbon Film 1/2 Watt Riken Ohm
1 - 500pf Capacitor
1 - 47pf Poly - Blue Cap -

Resistors/Caps on Pots and Switches
1 - Shrink wrapped to Pot - 100K Carbon Film 1/2 Watt Riken Ohm
1 - 500pf mica
1 - 100pf mica
1 - METAL OXIDE VARISTORS VZC 130v


Resistors/Caps on Tube Sockets
2 -2K - Carbon Film 1/2 Watt Riken Ohm
2 -100K - Carbon Film 1/2 Watt Riken Ohm
6 -1N4007 Diodes Mouser P/N: 833-1N4007
1 -47k Carbon Film 1/2 Watt Riken Ohm
2 -1K Vitreous Enamel 5W Wirewound Resistors (Green Resistors)

Other
2 - Bumble Bees to Ground - Value?
1 - Trim pot on Power Supply - Value/Brand?

[UR12]

The Trim pot is 25k and the Bumble Bees you refer to are 3watt 100k resistors. Don't forget the Transformers.......

[martins3325]

Thanks for the clarification on the bumble bee resistors. I think my list is comming along well. I have the Two Rock Ruby Transformers and Chassis so thats a given. I hear they didnt quite get it right though so Im going with the Fran build instead. Urban legend has it that they got a real express and reverse engineered it..trannies and all..which is why its surprising why they didnt get it right and added a MV and a effects loop. I wouldnt mind having a MV and a loop --so use the amp as a slave for re-amping-- but not at the detriment of getting it right. We'll see maybe once im done i'll try to add those things if its not too invasive to see if they hurt it much

[hot_tube_tone]

Would a Mouser number: 531-PTC10H-25K work for a BIAS Trim Pot? If not what would be a better one that Mouser offers?

[gearhead]

Have you had a chance to start on your express? Has your list worked out well?

BTW, what is a Two Rock kit? Were they selling off old stuff lying around?

All, is there any consensus on what iron (that is available today) to use for an Express?