Deconstructing the 102 BOM poll

[Luthierwnc]

By way of introduction, I'm rebuilding two D amps. One is a 50-watt 2nd gen that is almost done. The other is a 102 variant with an internal loop. Both were good sounding amps but a little noisy. I'm spending a lot more care on the lead dress and using more selected small components in all new boards.

In sifting through thousands of posts on parts and materials, I've found a lot more about items that aren't available than ones that are. The idea behind this poll is to ask everyone if they received a contract to make ten 100-watt 1980's D-clones a month, what would you use in the categories listed below.

I'm looking for stuff that is either currently being made or so recently out-of-production that you don't need to know somebody in Minsk to get it. If you simply must include something rare, put it in after your current-production recommendation. If you don't have an opinion, just skip that item.

Thanks for looking and for your ideas. Maybe this could become a sticky or a D-file thread if the results are noteworthy, sh

Resistors:
plate
slope
signal
preamp cathode
screen
preamp grid
power tube grid
bleeders
power supply

Caps:
Power supply
coupling
bypass
bias/relay supply

Chassis:
aluminum
steel

Pots:

Wire and Coax

Preamp tubes:

Power tubes:

Have fun and Merry Christmas!

[Duble]

Long time lurker, first time poster here. I've had great results with these:

Resistors:
Plate: NTE HW (Availible at Radio shack) or Koa Speer MF1/2CC
Slope: Koa Speer carbon Film "CF1/2"
Signal: Koa Speer carbon Film "CF1/2"
Preamp cathode: NTE HW or Koa Speer MF1/2CC
Screen: Xicon 5w Ceramic "Sandbox" or Koa Speer 3w "MOS3CT"
Preamp grids:
V1a: Koa Speer MF1/2CC
V1b: Koa Speer carbon Film "CF1/2"
V2a: Koa Speer carbon Film "CF1/2"
V2b: Koa Speer MF1/2CC
Power tube grid: Koa Speer 3w Oxide "MOS3CT"
Bleeders: Xicon 1w Metal Oxide "RC"
Power supply:
270k 1st Stage: Xicon Metal Oxide 3w "RC"
3k 5w: Koa Speer 3w Oxide "MOS3CT"
Dropping Resistors:
Koa Speer 3w Oxide "MOS3CT"
Bias: Xicon Carbon Film "RC"

Caps:
Power supply:
220uF's: "U" Brand at CE Distribution 220uF @ 350v
47uF 350v and 250v: Nichicon "667-EEU-ED"
Coupling: Sprague 6PS or Nichicon 630v Polyester "QXK2J series"
Bypass: Nichicon TVX 50v
Bias/relay supply: Nichicon TVX 160v Bias, Nichicon TVX 35v Relay Supply

Pots: Alpha 24mm (Mouser # RV24AF-10-15R1)

Wire and Coax: 20Awg Solid Core (tinned Copper 600v PVC insulator), RG188/U Coax (with white Teflon Insulator)

Preamp tubes: JJECC83 at Tube Depot, they test for lowest noise and triode balancing

Power tubes: TAD EL34 or 6L6 at CE Distribution.


I suppose CE is the best place for a "Clone" chassis but I make my own chassis in a free CAD program called EMachineshop. I make my own graffics and have local shops laser cut, break, and screen print it for me at about $140 per unit. I get my transformers made to my specifications at Heyboer.

Edit: I make all my circuit boards in EMachine Shop too, and have a friend of mine drill them on a CNC machine so they're a drop in fit to my chassis. I use an insulator board and top eyelet board made out of .063" Garolite material. One 12"x12" piece does 1 whole amp.

[Luthierwnc]

Looks a bit like mine, actually.

The emachineshop software is great. I've been using it for 4-5 years. There is a laser-cutting CNC shop about three miles from my house. The price is about the same as you pay for 1/8" stock, and welded corners. Absolute precision, no burrs. Plus, you can adapt the image for the faceplate templates and be spot-on.

Plates: RN65s
grids: KOA SPR2 or Kiwame
preamp cathodes: Takman MF 1 watt
most signal resistors: Takman CF (MF on V1a)
slope: usually a CCF60 (Mouser) but haven't been consistent
bleeders: whatever, multi-megohms are usually CC
power supply and screens: Dale 3W wirewound RS02B... series
Assorted metal oxides downstream

Caps:

6Ps, F&T filters, nichicon filters for totem-pole builds, assorted small radials for bias and relay supply, Nichicon axial bypass caps (the kind Doug Hoffman sells)

Tubes: TAD 6l6's, preamp; I cheat and usually get ANOS GE short-plates on Ebay but I've used the Mullard RI's too and they worked fine.

Printed boards I make myself with a mixture of 2X peroxide and 1X muratic acid in a warm water bath. Takes 4 minutes. Usually I get the image laser copied on magazine paper and iron it on the board but printers are so efficient anymore that I usually have to retrace the lines with a Sharpie after I soak the paper. They are crude with large traces so it works fine. If I was making an iPhone, I'd be more demanding.

Keep those ideas coming! sh