From AIWA TP-1011 mic preamp to a standalone pedal... [schematic]

[Wlat]

Hi!
Just found this thread, and I'm EXTREMELY exited about it!
I've just made the schematic in Eagle and I'd like your opinion.
When I compare the original Aiwa TP-1011 schematic to the v1.35 by gilmour_pugliese (GREAT work!!!) I'm a bit confused by the following:
In the Aiwa schematic there seems to be no connection between 100p/22k/5uF junction and the T2 collector / 5uF junction.
In the v1.35 schematic there is a connection (C5 - C6).
What do you think?

Any thought on replacement transistors? John "Dawk" Stillwell says on his forum he replaced the originals with quieter ones.
Anyway, here's my Eagle schematic:

[ppcnostalgic]

Hi. The schematic looks a little different from the one I used. I also made a different veroboard to fit a charge pump and few other stuff on the same circuit., it works fine. If you need my schems and / or my veroboard layout send me a PM and provide me your mail address, I'll send you all the things. Cheers

[progulus]

Cheers mate, I might try building this and see how it works with my 5 Watt Legacy Valve Custom 5 Plus amp....

Let me know if you like this preamp... Today I've boxed my circuit (with a 1054 charge pump) and tested in various setups: Laney VC15, my DIY Hiwatt Custom 50 and even with a POD and works great... In my next components order I've put a 1M lin pot for out cap blending because a 100k have a limitate range...

By the way, here's the ultimate layout... same as the last but with some corrections on the out cap blending scheme

Hi all, I'm a first time pedal-builder. I built this one excatly to gilmour_pugliese's "ultimate layout" veroboard diagram on page 4 of this thread, with the additional 100k resistor pointed out by deafbutpicky. The pedal works pretty good at fattening up my tone, and as an 'always-on' saturation boost.

I triple checked all of my wiring and still have a couple of problems with the build that I hope somebody here could address:

1. The gain pot is working in reverse... turning it all the way clockwise is 'off'. I don't really understand how it is possible, but this is what's happening. Is there an error in gilmour_pugliese's wiring diagram? I can't really tell but maybe someone could double-check that the veroboard diagram is correct.

2. There's a rather annoying high pitch whine that shows up when the pots are turned up more than 25%. It's not really 'noise' like you would normally hear, but this is a pretty distinct frequency- based whine.

A few other notes regarding the build; Unless you are trying to deliberately overdrive this pedal, I think it sounds best when the gain knob is turned totally off. There could use some tweaking with the pots, any one of them up about 1/4 the way maxes it out, and adds the noise/whine as described above. The saturation pot is particularly sensitive to this (I did use a 25k pot here instead of the specified 20k because that's what the vendor was offering).

Thanks!

[progulus]

Cheers mate, I might try building this and see how it works with my 5 Watt Legacy Valve Custom 5 Plus amp....

Let me know if you like this preamp... Today I've boxed my circuit (with a 1054 charge pump) and tested in various setups: Laney VC15, my DIY Hiwatt Custom 50 and even with a POD and works great... In my next components order I've put a 1M lin pot for out cap blending because a 100k have a limitate range...

By the way, here's the ultimate layout... same as the last but with some corrections on the out cap blending scheme

Hi all, I'm a first time pedal-builder. I built this one excatly to gilmour_pugliese's "ultimate layout" veroboard diagram on page 4 of this thread, with the additional 100k resistor pointed out by deafbutpicky. The pedal works pretty good at fattening up my tone, and as an 'always-on' saturation boost.

I triple checked all of my wiring and still have a couple of problems with the build that I hope somebody here could address:

1. The gain pot is working in reverse... turning it all the way clockwise is 'off'. I don't really understand how it is possible, but this is what's happening. Is there an error in gilmour_pugliese's wiring diagram? I can't really tell but maybe someone could double-check that the veroboard diagram is correct.

2. There's a rather annoying high pitch whine that shows up when the pots are turned up more than 25%. It's not really 'noise' like you would normally hear, but this is a pretty distinct frequency- based whine.

A few other notes regarding the build; Unless you are trying to deliberately overdrive this pedal, I think it sounds best when the gain knob is turned totally off. There could use some tweaking with the pots, any one of them up about 1/4 the way maxes it out, and adds the noise/whine as described above. The saturation pot is particularly sensitive to this (I did use a 25k pot here instead of the specified 20k because that's what the vendor was offering).

Thanks!

Edit to my original post - the whine I was experiencing seems to be coming from my power supply. I added a ferrite magnet on the cord and it cut down the noise considerably.

[progulus]

I want to thank all of the people here who worked so hard to put this thread together. I love this pedal and consider it my "always on" secret weapon to fatten and saturate my tone. This pedal is definitely worth taking the time to build. If anyone is looking for a 18V power supply, I've found that the Dunlop MXR ECB004US Barrel 18V Adapter works well.

I'd like to offer a couple of suggestions for improvements/mods that I've made to my V2 pedal. As I mentioned in previous post, I originally built my pedal exactly to spec using the information here provided by gilmour_pugliese. I attached the original schematics that he provided for reference.

The first, and this is a biggie, is to get rid of the 'whine' that the pedal produces. I can't believe anyone who has built this hasn't had mentioned this problem. At first I thought it had to be my power supply, but after troubleshooting I determined that was not the cause. The problem is that the 1M resistor at R2 is I believe functioning as an impedance pulldown at the input, but it's still too high (with a guitar). Digging back a ways into this thread reveals that this resistor seems to have been selected somewhat arbitrarily. By changing R2 to a 100K resistor this whine is almost completely eliminated. I added the 100k resistor in parallel with the existing 1M, but that's only slightly lower than 100k on its own, so future builders should just use a 100k in place of the 1M.

Second, and more minor, is that all of the pots were too sensitive and almost fully saturated at the 9:00 position. On my V2 build I reduced the gain pot to a 25k, volume pot to a 10k, and saturation pot to a 5k. The saturation pot could possibly be reduced even further to 1-2k because even at 5k it's still very sensitive. Also the gain pot functions backwards (counter-clockwise) no matter which way the wires are connected to it, so possibly an inverse (C) pot is required here?

That's what I've found so far. I hope it helps.

[mojah63]

I want to thank all of the people here who worked so hard to put this thread together. I love this pedal and consider it my "always on" secret weapon to fatten and saturate my tone. This pedal is definitely worth taking the time to build. If anyone is looking for a 18V power supply, I've found that the Dunlop MXR ECB004US Barrel 18V Adapter works well.

I'd like to offer a couple of suggestions for improvements/mods that I've made to my V2 pedal. As I mentioned in previous post, I originally built my pedal exactly to spec using the information here provided by gilmour_pugliese. I attached the original schematics that he provided for reference.

The first, and this is a biggie, is to get rid of the 'whine' that the pedal produces. I can't believe anyone who has built this hasn't had mentioned this problem. At first I thought it had to be my power supply, but after troubleshooting I determined that was not the cause. The problem is that the 1M resistor at R2 is I believe functioning as an impedance pulldown at the input, but it's still too high (with a guitar). Digging back a ways into this thread reveals that this resistor seems to have been selected somewhat arbitrarily. By changing R2 to a 100K resistor this whine is almost completely eliminated. I added the 100k resistor in parallel with the existing 1M, but that's only slightly lower than 100k on its own, so future builders should just use a 100k in place of the 1M.

Second, and more minor, is that all of the pots were too sensitive and almost fully saturated at the 9:00 position. On my V2 build I reduced the gain pot to a 25k, volume pot to a 10k, and saturation pot to a 5k. The saturation pot could possibly be reduced even further to 1-2k because even at 5k it's still very sensitive. Also the gain pot functions backwards (counter-clockwise) no matter which way the wires are connected to it, so possibly an inverse (C) pot is required here?

That's what I've found so far. I hope it helps.

What's the gain (HFE) of your transistors? I'm revisiting old builds and fixing them or in some cases rediscovering them. I remember mine never sounded right but I think I had high gain modern transistors in all positions. Not sure what Q1's gain range should be but Q2 according to the old Japanese 2sc733 2sc732 data sheet is 200 -400 and Q3 if is an O grade 70-140, Y grade 120-240..

[Manfred]

What's the gain (HFE) of your transistors? I'm revisiting old builds and fixing them or in some cases rediscovering them. I remember mine never sounded right but I think I had high gain modern transistors in all positions. Not sure what Q1's gain range should be but Q2 according to the old Japanese 2sc733 2sc732 data sheet is 200 -400 and Q3 if is an O grade 70-140, Y grade 120-240..

I found in the Radiomuseum forum further data concerning the transistors.
https://www.radiomuseum.org/tubes/tube_2sc369.html
https://www.radiomuseum.org/tubes/tube_2sc733.html
https://www.radiomuseum.org/tubes/tube_2sc372.html

You can see there that each transistor type got different gain groups.
I suppose that AIWA had selected the transistors in this time of production.
A wrong gain gives a wrong bias point and, as a result is a unwanted sound.

For a recalcualtion to find the appropriate gain of each transitor the read voltages values on its pins are required.
Is there anyone who knows this values?

[progulus]

On my build, I used 2X BC549C and 1X BC549A. My noise problems haven't been removed, but reduced with my fix. If I place the pedal between the guitar and amp (regardless of how many effect pedals is in the chain) I get the whine... , when the pedal is placed between the A/D/A processor and the amp the whine goes away totally... so the problem is at least aggravated by a high impedance.

[mojah63]

On my build, I used 2X BC549C and 1X BC549A. My noise problems haven't been removed, but reduced with my fix. If I place the pedal between the guitar and amp (regardless of how many effect pedals is in the chain) I get the whine... , when the pedal is placed between the A/D/A processor and the amp the whine goes away totally... so the problem is at least aggravated by a high impedance.

I'm using 2 x BC549B hFE ~330 and still experimenting with the A gain slot. It's a pretty woofy circuit as is. I think people forget Blackmore used it to bludgeon the brilliant channel of a Marshall Major which has a .002uf coupling cap between stages so a lot off bass is stripped out from the amp and it may have had a factory cascading preamp mod still in when the tape recorder showed up. Also at first he used the tape recorder as a delay until it broke. Dawk did more more mods in Rainbow... I'm moving on to a Throback overdriver next..

[Wlat]

On my build, I used 2X BC549C and 1X BC549A. My noise problems haven't been removed, but reduced with my fix. If I place the pedal between the guitar and amp (regardless of how many effect pedals is in the chain) I get the whine... , when the pedal is placed between the A/D/A processor and the amp the whine goes away totally... so the problem is at least aggravated by a high impedance.

I'm using 2 x BC549B hFE ~330 and still experimenting with the A gain slot. It's a pretty woofy circuit as is. I think people forget Blackmore used it to bludgeon the brilliant channel of a Marshall Major which has a .002uf coupling cap between stages so a lot off bass is stripped out from the amp and it may have had a factory cascading preamp mod still in when the tape recorder showed up. Also at first he used the tape recorder as a delay until it broke. Dawk did more more mods in Rainbow... I'm moving on to a Throback overdriver next..

Afaik, there was a (Dawk built?) treble boost mod in the Marshall Major. That took some of the "woof" out, I guess. BSM supposedly built a Blackmore booster based on the combination of the Aiwa and this treble boost?

[progulus]

weisd.com appears to sell transistors equivalent to the 2SC369, 2SC733, and 2SC372. Would it be worth trying these?