Lee_M
Well-known member
I'm currently working on a clone of the "Peterson" preamp to use with my Fender Rhodes stage 73. The original design uses a pair of GE #19 miniature bulbs (14.4v, 0.1A, bi-pin), but these are very hard to find for reasonable prices nowadays, at least on this side of the Atlantic. There's a few US-based sellers who want a couple of dollars per bulb or less, but shipping costs make buying from them prohibitive, if they even offer shipping to the UK. The only UK-based seller wants £5.40 per bulb, which would be fine if I just wanted one or two, but I'm planning on building 10 of these preamps (the PCB fab house I use doesn't do 1pc board orders, and 10pcs is fairly cheap), which means I need 20 bulbs in total, and I'd rather not spend over £100 on a handful of miniature light bulbs to populate all of the boards.
The cheapest option I can find is a US seller who wants $67.30 (Just over £50) for 20pcs including postage, but I'll still have to pay customs fees (normally around 20%, possibly with a handling charge) on top of that.
Here's a schematic of the preamp.
http://www.fenderrhodes.com/org/ch11/fig11-8.jpg
Since I'm designing the boards from scratch, I'm wondering if I can just use any ~14.4v ~0.1A bulbs in place of the obsolete #19 bulbs?
I've found these, which are a close match for voltage (14V, about 3% short of 14.4V) and use slightly less current (0.08A), and most importantly, I could buy 100pcs for about the same price as 20pcs of the #19 bulbs.
https://www.mouser.co.uk/ProductDetail/VCC/8640?qs=GLfira415aBJBLuWs9BrSw==
They're marked "Not recommended for new designs", but I'm only building 10 of these preamps, and buying 100pcs of those bulbs from Mouser should give me a lifetime supply of spare bulbs.
The big question is; Will different bulb types (specified for similar voltages) react differently to the varying voltages being fed to them as part of the tremolo circuit, or will any suitable (in terms of voltage and current) incandescent bulb behave in roughly the same manner?
The cheapest option I can find is a US seller who wants $67.30 (Just over £50) for 20pcs including postage, but I'll still have to pay customs fees (normally around 20%, possibly with a handling charge) on top of that.
Here's a schematic of the preamp.
http://www.fenderrhodes.com/org/ch11/fig11-8.jpg
Since I'm designing the boards from scratch, I'm wondering if I can just use any ~14.4v ~0.1A bulbs in place of the obsolete #19 bulbs?
I've found these, which are a close match for voltage (14V, about 3% short of 14.4V) and use slightly less current (0.08A), and most importantly, I could buy 100pcs for about the same price as 20pcs of the #19 bulbs.
https://www.mouser.co.uk/ProductDetail/VCC/8640?qs=GLfira415aBJBLuWs9BrSw==
They're marked "Not recommended for new designs", but I'm only building 10 of these preamps, and buying 100pcs of those bulbs from Mouser should give me a lifetime supply of spare bulbs.
The big question is; Will different bulb types (specified for similar voltages) react differently to the varying voltages being fed to them as part of the tremolo circuit, or will any suitable (in terms of voltage and current) incandescent bulb behave in roughly the same manner?
