Get a BC517 Darlington along with it just in case your chatter persists, so to know if it is an alternative solution to the extra cap, if you fancy.
From Ferds to Tea, life's a helter skelter ride man.
Who was meditating over piano ballads only, again?
My proto Hypnotize arrived today along with the last lot of components - thanks Tea-Bag - I will try to get it up and running asap.
A question - I have tried measuring / matching the LED's (red ones as per BOM) and they all measure under 1.8v; is it OK to mix LEDs e.g. a Green at 1.96 would get me to the 9.0 requirement? Same would apply to the 5.4volt string. Pity I have no yellow ones!
My 7812 was sourced from Farnell and was made by STElectronics - I will report if it leads to chatter or not.
I was going to try a 12v relay but since I bought a lot of 6v NAiS relays (and sold them on to people) then I will start with the latter.
A question - I have tried measuring / matching the LED's (red ones as per BOM) and they all measure under 1.8v; is it OK to mix LEDs e.g. a Green at 1.96 would get me to the 9.0 requirement? Same would apply to the 5.4volt string. Pity I have no yellow ones!
My 7812 was sourced from Farnell and was made by STElectronics - I will report if it leads to chatter or not.
I was going to try a 12v relay but since I bought a lot of 6v NAiS relays (and sold them on to people) then I will start with the latter.
Salas - thanks - I had used your suggestion to measure the first few LEDs but having just bought a Peak Transistor tester I was using that to measure the LEDs - its test current varying between 3.3 & 3.5 mA. I will re-measure as per your diagram.
Alan
Anybody who is going to physically hold the PCBs is going to maybe feel that this is a very compact & straight made circuit, down to minimal for being a fully functioning discrete preamp with 2 regs. I am happy that you really enjoy it. I hope that will be at least OK for all. Surely it is relatively economical for space and money. No bulky exotic Teflon$ needed.
P.S. Did you restore your CJ tube pre by now? All well?
P.S. Did you restore your CJ tube pre by now? All well?
Salas,
A quick question about the power supply if I may, the regulated outputs are fine, but I did a voltage check across R5, the 10 ohm resistor, on the positive and negative regulators. The positive reg has approx twice the voltage across R5 (174mV) as the neg reg's R5 (83mV). Is this normal operation? Just wondering where the extra current is going...
Ian.
A quick question about the power supply if I may, the regulated outputs are fine, but I did a voltage check across R5, the 10 ohm resistor, on the positive and negative regulators. The positive reg has approx twice the voltage across R5 (174mV) as the neg reg's R5 (83mV). Is this normal operation? Just wondering where the extra current is going...
Ian.
Hypnotize Board
Tea-Bag,
I have a problem with the Hypnotize board, there are two chains of 5 LEDs with one of them I have soldered the five LEDs without a hitch. However with the second set (the ones just above the legend 'Hypnotize) I found that after soldering them in a couple of them were loose - it seems that somejhow the track has lifted and broken - this is the first soldering on the these pads - no desoldering.
I will be able to continue with the build by soldering a new set of LEDs point-to-point.
Has anyone else seen this?Do we need thicker copper? Do I need to improve my soldering?
Alan
Tea-Bag,
I have a problem with the Hypnotize board, there are two chains of 5 LEDs with one of them I have soldered the five LEDs without a hitch. However with the second set (the ones just above the legend 'Hypnotize) I found that after soldering them in a couple of them were loose - it seems that somejhow the track has lifted and broken - this is the first soldering on the these pads - no desoldering.
I will be able to continue with the build by soldering a new set of LEDs point-to-point.
Has anyone else seen this?Do we need thicker copper? Do I need to improve my soldering?
Alan
I also faced same issue - but consider same solution as directly attaching the LEDs Leads to the next one
kannan
i dont think anyone with a mesmerize has done this, which uses immersion gold vs tin. Just a thought. But, its liable to get cooked off, being so small.
Make Gold IMO. They are vey cheap for what they do anyway. LED area is probably the place where they gonna exchange Leds or add resistor to go other Vout if used for shunt only. And most of the people asking the Hypno are looking for a shunt, not a pre. They want the regs. Sneaking the Salasity out of the Hypnosity.
That's my guess.
I was trying to keep a larger price difference between Hypnotize and Mesmerize, I didn't think this sort of thing would be a result. The price difference here is about 30 cents a board extra for Hypnotize to go gold.
Consider the price of the Hypnotize to have just gone up.
I think that the cost of the boards is so small compared to all the parts / case etc that a small increase is acceptable.That's my guess.
I was trying to keep a larger price difference between Hypnotize and Mesmerize, I didn't think this sort of thing would be a result. The price difference here is about 30 cents a board extra for Hypnotize to go gold.
Consider the price of the Hypnotize to have just gone up.
So gold it is??
Alan
How much did it cost you BTW? You use a very good assortment of parts and a an SMD Vishay resistor switcher pot. Its a good indication for those looking to build fully functional a preamp and use it. You miss the box for now I guess, but it is not rational to include the box in the cost estimation anyway. There someone can go from tin can to exotic. Its looks.
Well, the proto builders get to weigh in and we can make a decision. I think gold has a different point of overheating. A lot of builders dont like gold. We could go thicker as well, but for a pre I think it's overkill. It's a sensitive area on the LEDs.
With my iron at 900F on a gold pad, I can burn it off
So this is a good construction note concern anyways. This area is likely a place to be careful.
My opinion is low-melting point lead solder is a way to go here. I have used so many crap solders. I love cardas. Worth the money.