Rangemaster cap question (Madbean RM)

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OnTheTundra
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Post by OnTheTundra »

Hey all,
Quick question.
I put together a mad bean Rangemaster with an OC 44 I bought from small bear. It calls for sprague atom electro caps. I didnt have any of these and it says that only the 47uF caps HAVE to be electro. So I used regular axial electro caps from my local electronics store (Norvac) Then I used orange drops for the other 2X 10nF and 1X 5nF. Ive built two of these and they both have weak distorted signals. I am wondering if the values are wrong for the three caps that I used orange drops on. I cant seem to find Sprague atom electro caps for those values. Should I put some 10uF and 5uF electro caps in place of the drops? Please help. Thanks. Heres the link to the file: http://www.madbeanpedals.com/projects/R ... r_ver1.pdf
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jimbob_400
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Post by jimbob_400 »

OnTheTundra wrote:Hey all,
Quick question.
I put together a mad bean Rangemaster with an OC 44 I bought from small bear. It calls for sprague atom electro caps. I didnt have any of these and it says that only the 47uF caps HAVE to be electro. So I used regular axial electro caps from my local electronics store (Norvac) Then I used orange drops for the other 2X 10nF and 1X 5nF. Ive built two of these and they both have weak distorted signals. I am wondering if the values are wrong for the three caps that I used orange drops on. I cant seem to find Sprague atom electro caps for those values. Should I put some 10uF and 5uF electro caps in place of the drops? Please help. Thanks. Heres the link to the file: http://www.madbeanpedals.com/projects/R ... r_ver1.pdf
Have you included the switch or just put the 5nf and 10nf in parallel with each other? 10uf and 5uf is way to high. The 47uF filter capacitor will be fine. What is the hfe of the OC44 you have put in the circuit?
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OnTheTundra
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Post by OnTheTundra »

the switch is included, I'll go check the hfe and get back to you. By the way, the transistors came with the two resistors (3.9K and 68K) but they were different values depending on the transistor. One was 3.2 and 62, and the other build was 3.9, and 58. These were used instead of the layouts 3.9 and 68 because I figured they sent them to match the transistors.
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azrael
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Post by azrael »

Do you have a multimeter?

Can you measure the voltages on the legs of the transistor?
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mojah63
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Post by mojah63 »

All you need to know here:

http://www.geofex.com/Article_Folders/R ... tboost.pdf


It's the fx I always keep going back to. I made all mine with a compensating
diode for temperature as here:

http://fuzzcentral.ssguitar.com/rangemaster.php

You need a multimeter and a good eye to trouble shoot your problem.

Check your layout and wiring, soldering too. Boards clean b4 soldering?
Blobs? Wrong component in wrong location? Transistor biasing should be
ok if you put the matched resistors in the right places.. Transistor orientated
correctly? Base, Emitter, Collector? Read the pdf it tells
you how to check the bias.
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