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91
Tech Help - Projects Page / Re: Aquaboy -- Can I sub 2n5088 in place of MPSA18?
« Last post by U4U on November 19, 2017, 02:46:16 PM »
Hi, I always use 2N5089 instead for distortion or overdrice pedals, if 2N5088 are used, but I wouldn't on a delay! 
92
Tech Help - Projects Page / Re: Rub a dub deluxe issue
« Last post by U4U on November 19, 2017, 02:43:40 PM »
..works now, had some issues with the switchcraft jacks! Great device, but not half as good as my Hardwire Supernatural, of course, but very different sounding!
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Open Discussion / Re: Submini question - tis the season!
« Last post by Scruffie on November 19, 2017, 01:45:34 PM »
Ohm's law.

It's all about current draw and voltage drop, the heaters draw a LOT of current so if you wanna drop the voltage down 6V, you're going to need a hefty wattage resistor to stop it frying. For the filtering, a larger value resistor can be a smaller wattage but will drop more voltage, the plates don't draw a huge amount though, a few mA but it depends on your supply.
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Open Discussion / Re: Submini question - tis the season!
« Last post by zombie_rock123 on November 19, 2017, 01:37:06 PM »
Awesome, thanks for the reassurance and info guys!

The big-assed resistor usually seen on these things - I'm guessing it's usually to drop the 9/12/18 volts to 6 for the heaters, but in the Subcaster there's a (presumably) big wattage/low value resistor for the supply to the plates. If you don't need the 6 volts for the heaters is it just a case of using a small value honkin great resistor for filtering given the amount of juice it's going to draw? I can't believe I'm actually going to have a use for a sub-10R 5 watt resistor...
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Open Discussion / Re: Submini question - tis the season!
« Last post by madbean on November 19, 2017, 01:28:02 PM »
Yeah, I agree: if you like the sound that's what matters. I have found in some cases that 6.3v vs. 6v can make a big difference (surprisingly) but only with a single tube. With two heaters in series maybe it's different, or maybe that was just a special case.
96
Open Discussion / Re: Submini question - tis the season!
« Last post by Scruffie on November 19, 2017, 01:19:26 PM »
If you're happy with the sound, I wouldn't worry. Under voltage is a lot better than over voltage, the Valvecaster uses a 12AU7 at 9V instead of 12V for the heaters, it just means the tube isn't going to be running to the datasheet specs with the added benefit it might live a bit longer.

IIRC the 6N16 is 6V+/-300mV anyway so 5.5V isn't that far off and as you say, going for 18V (or having them in parallel with a 6V regulator from the 12V supply) is a bit overkill and adds its own headaches.
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Open Discussion / Submini question - tis the season!
« Last post by zombie_rock123 on November 19, 2017, 12:33:01 PM »
With all the submini projects in the Beanpipe I thought Id have a go at breadboarding something. I put together a subcaster, tacked on another 6N16 tube, added a tone stack. I was thinking that I could just run the heaters in series to avoid buying a 317, 6v reg or huge resistor. 12 volts / 2, job done, also works fine for the plates.

Sounds amazing, really love these little things but I think I might have an issue. My PSU is 12v 1.5A and when I've measured the heaters I'm getting less than 6volts on each, round about 5.5, and from my googling before I started in this topic someone mentions that series-ing them isn't that good as 6 is the absolute minimum:

http://www.diystompboxes.com/smfforum/index.php?topic=66746.40

So my question is, do I not care about the voltage difference, or do I hook them up a different way? The only way I can think is to power it with an 18 volt PSU with a 12 volt reg for the heaters. But this seems overkill really.

Typing all of this out I have realised that I have no filtering yet - no small value/large watt resistor to separate the power for the plates from the heaters. If this is my problem then I feel like a jackass. But still wondering if that isn't likely to be the issue :) Still trying to get a handle on the whole regulator/massive resistor thingy and series-ing them seemed to be too good to be true!
98
Build Reports / Re: A couple quick builds
« Last post by EBK on November 19, 2017, 12:21:49 PM »
Seems weird to say this, but the minimalist labeling is beautiful.
99
Tech Help - Projects Page / Some issues with a L5 Preamp
« Last post by U4U on November 19, 2017, 10:33:17 AM »
Hi, just build a second one, but had some issues with this one. Channel switching works, but both channels produce ugliest distored flat sound! Soldering was done very clean, no visible short circuit...

Issues
1. Bypass works, but LED is always on
2. Limit LED is always on
3. Flat distored sound on both channels

ICs:
IC4 - IC9, IC12: RC4558P
IC1: LF356N
IC2, IC13: LM741CN
IC10-IC11: CA3080AE

Semiconductors as described and most of the parts are ordered from Mouser, but replaced some 10% Wima caps mentioned in the parts sheet with 5% Wima caps. The  distored sound seems to be an issue depending on the switchcraft jacks, which obviously do not work properly. They seem to offer some space and the plugs seem to be shaky this way which results in flat and distored sound.
 

Maybe someone runs into equal issues or has an idea what happens here. I have used a plain enclosure for the first build and a black enclosure sold by aion for this build.

Thanks a lot

U4U
 




100
Open Discussion / Re: Help me identify this SMD transistor
« Last post by BuGG on November 19, 2017, 10:18:45 AM »
Thanks man, 5089 sounds about right for this circuit.

PM me your info and I'll ship you a board as soon as I get them.
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