Dallas Rangemaster: voltage collector

[ricci]

What npn transistor did you use ?

Just yesterday I tried the following NPN in negative ground configuration: BC547 2N1711 BC337 AC127 BC237
the rustle was absurd, the BC237 the quietest. I tested this by keeping my 60W amp volume at 50% and the RM gain at maximum. The audio recording has been done with the mobile phone placed on the table at a height of 50 cm with respect to the speaker, therefore not frontally. The circuit is trivial enough to have something wrong. Is it possible that my transistors are all faulty? Could the carbon resistors cause such a noise?
I attach the small audio files.

AC127 https://voca.ro/1oi5RYfzg2dA
2N1711 https://voca.ro/19oP8NvhoNRm
BC337 https://voca.ro/1j2PWTUxlbS9
BC547 https://voca.ro/15cZu1FeUf15
BC237 https://voca.ro/1s8KHZLw4hfl

[willienillie]

Assuming you recorded all these clips the same, the differences in hiss volume are significant.  So if the only variable is the transistor, there you go.  I built one with a Mullard OC76 a few years ago, it had quite a bit of hiss.  My newer build with the 2SB175 is very quiet.  Carbon comp resistors can contribute some noise, but in my experience the worst usually comes from the active components.  Still I use metal films in this circuit though, just because it's so trebly.

[iainpunk]

the original range master i played was really noisy as well. the clone was not. they had both used an OC71, the clone has fancy glass capsule wire wound resistors and tropical fish caps and a see through case to show off the fancy components and paper-Bakelite PCB. the guitar player with the clone told us he payed 250 euro for the range master clone. i was dumbfounded... 250 euro?!?!?! granted, it looks cool, but that price is ridiculous

cheers, Iain

[duck_arse]

here we are, page three. you are still having problems, we still, still, haven't seen any pictures of your board or build or wiring. please can we see some photos of your build?

[iainpunk]

here we are, page three. you are still having problems, we still, still, haven't seen any pictures of your board or build or wiring. please can we see some photos of your build?

OT: you can change the amount of replies per page, i like them as high as possible, which is 50
profile > look and layout > somewhere near the bottom

[ricci]

Guys, if my requests / doubts can annoy someone, tell it now so I will provide. In any case, to dispel any doubts about poorly made wiring or soldering, I am attaching photos of my built.

[ricci]

Assuming you recorded all these clips the same, the differences in hiss volume are significant.....

I still tried the positive ground pnp but with the charge pump 7660S and that noise has gone away but a hiss remained.

[Big Monk]

Assuming you recorded all these clips the same, the differences in hiss volume are significant.....

I still tried the positive ground pnp but with the charge pump 7660S and that noise has gone away but a hiss remained.

Where did you purchase the transistor? Some germanium devices are simply more hissy than others.

[ricci]

Where did you purchase the transistor?

at the fair about 15 years ago

[duck_arse]

ricci, you are not causing any annoy with questions or doubts. carry on.

but, when you show this photo ....



.... we immediately ask, why do you have a 680k resistor and a 470k resistor when the circuit diagram [a wonderful, enlightening thing] shows a 470k and a 68k?

now, see, why I allays ask? please, use your multimeter, measure that resistor, and tell us what value it reads.

[is everybody/anybody having long waits to load this page?]

[ricci]

it is orange not yellow

[PRR]

...[is everybody/anybody having long waits to load this page?] ...

Image in reply #50 never loads.

Two images in reply #45 load fine but resolve to a different site than the link indicates.

PostImg may be having a bad day (or two).

[Big Monk]

I'm going to reiterate the obvious here: You may just have hissy transistors.

[ricci]

I'm going to reiterate the obvious here: You may just have hissy transistors.

It is very likely. Curious however that using the charge pump all noise go away but that hissing remains. I'll try to use some shielded wire.

[idy]

To confirm the noisy tranny theory you use the gain tester that also test leakage.
http://www.geofex.com/article_folders/ffselect.htm

Making this is another little rite of passage. If you like Ge. Mine is in a cute little box.

[Electric Warrior]

In my experience, leaky transistors are not necessarily noisier in this circuit than low leakage ones. OC44s often have no leakage at all and they're about as noisy as OC75s which leak a lot...

[duck_arse]

it is orange not yellow

excellent. if I'd looked at the other photo, I might have seen the odd differences your camera/ hosting site produces. my apologies.






[images seem to show ok. redirect code isn't obvious. page seems normal speed now.]

[ricci]

...I might have seen the odd differences your camera/ hosting site produces.

Certainly, hosting site 

[ricci]

Have you tried positive ground and a battery?

Yes, I have tried the positive ground even with the battery and the hiss is the same and I have also verified that the NPN is less noisy.

I know my NPN Rangemaster has no hiss even at top volume. I use a regulated power supply feeding all my pedals.

But in order not to hear hiss even at the top of the volume, which NPN transistor did you use?

However, in reality, I already have the Analogguru booster working and very quiet but I wanted to replace it with a two-output Rangemaster, a treble boost with 5nF in input when I use the tube and a full boost with 22nF for the quieter things.

[ricci]

I have adjusted the bias with a trimmer and i would like to know if there could be problems of instability leaving the trimmer without putting the fixed resistance?

I have another question...anyone know about AC142K pnp transistor? I have read that they are very quiet, can anyone confirm this?