Another victory for the SD Pickup Booster!

[leevc5]

I finished building my 5f1 tweed Champ clone amp and plugged her in and played in eager anticipation (redundant but true). Disappointment followed as the sound was flat and lifeless. I switched tubes JJ 6V6, 12AU7, Tung SOL 12AX7, Copper Cap Rectifier, swapped OT wires, changed resistor values in inputs and bridges...nothing helped. I was really bummed. I was at the point of searching the WEB for tube amp heads. Then I saw my Pickup Booster and hooked it up (during the process I received a mighty shock from touching something wrong at the wrong time but survived).

Well enough story telling and off to the bottom line. Like magic the pickup Booster turned this lifeless contraption into an absolutely beautifully sounding amplifier.

Thank you Mr. Seymour Duncan and Company for creating this wonderful device.

I would really like to understand how the pup booster works if anyone can explain it in like a pedals for dummies format.

 

[Scott_F]

Re: Another victory for the SD Pickup Booster!

Why not a 12AY7?
12AU7 is lot lower in gain.

Glad you got it working!

 

[Demanic]

Re: Another victory for the SD Pickup Booster!

Got a thought that it's a clean boost with a mid cut.

Sent from my MotoE2(4G-LTE) using Tapatalk

 

[leevc5]

Re: Another victory for the SD Pickup Booster!

I finished building my 5f1 tweed Champ clone amp and plugged her in and played in eager anticipation (redundant but true). Disappointment followed as the sound was flat and lifeless. I switched tubes JJ 6V6, 12AU7, Tung SOL 12AX7, Copper Cap Rectifier, swapped OT wires, changed resistor values in inputs and bridges...nothing helped. I was really bummed. I was at the point of searching the WEB for tube amp heads. Then I saw my Pickup Booster and hooked it up (during the process I received a mighty shock from touching something wrong at the wrong time but survived).

Well enough story telling and off to the bottom line. Like magic the pickup Booster turned this lifeless contraption into an absolutely beautifully sounding amplifier.

Thank you Mr. Seymour Duncan and Company for creating this wonderful device.

I would really like to understand how the pup booster works if anyone can explain it in like a pedals for dummies format.

Reread this thing this morning( and it sounds like a commercial for a vegomatic or something...very naive and freshman post for sure(I don't drink so that is not an explanation). I was tempted to delete it but decided not. As corny as it is, it is the truth however shabbily wrapped.

 

[Artie]

Re: Another victory for the SD Pickup Booster!

The truth is a good thing. The pickup booster performs two functions:

1. As a buffer. Guitars are high impedance outputs. The buffer effectively converts it to a low impedance output. This relieves the pickup of any "loading" effects of whatever the guitar is plugged into.

2. Flat amplifier. Simply allows you to boost the gain in order to overdrive the input to an amp or compressor. The latter being one of my favorite things to do.

Enjoy. I love mine too.

 

[Diego]

Re: Another victory for the SD Pickup Booster!

The truth is a good thing. The pickup booster performs two functions:

1. As a buffer. Guitars are high impedance outputs. The buffer effectively converts it to a low impedance output. This relieves the pickup of any "loading" effects of whatever the guitar is plugged into.

2. Flat amplifier. Simply allows you to boost the gain in order to overdrive the input to an amp or compressor. The latter being one of my favorite things to do.

Enjoy. I love mine too.

I'm quite ignorant when it comes to electronics, but I understand the PB does something funny to the resonant peak of single coils and "humbuckerizes" their attack and response, too?
Is this effectively so?

I ask because I don't see that listed in your analysis, and from what you describe it wouldn't be that different from something like a Zvex SHO, but I understand they're not even close.

 

[Funkfingers]

Re: Another victory for the SD Pickup Booster!

Those amplifiers only get interesting when the volume control is most of the way up. Expect your neighbours to be banging on the door within minutes.

 

[Scott_F]

Re: Another victory for the SD Pickup Booster!

I still don't understand the tube choices. But if it's working, all power to you man. :friday:

 

[leevc5]

Re: Another victory for the SD Pickup Booster!

Those amplifiers only get interesting when the volume control is most of the way up. Expect your neighbours to be banging on the door within minutes.

Yeah! I can't believe how loud 1 6V6 can be and the overdrive is sweet.

I play in quick spurts just long enough to get the neighbors riled but not long enough for them to get up and over to my house.

 

[leevc5]

Re: Another victory for the SD Pickup Booster!

I still don't understand the tube choices. But if it's working, all power to you man. :friday:

I have a Tung Sol 12AX7 and a JJ 6V6, What would you recommend?

 

[Funkfingers]

Re: Another victory for the SD Pickup Booster!

I still don't understand the tube choices.

I think that was just a list of everything that got tested.

I do not know what options are open for the rectifier. This is more relevant to the dynamics than the drive or the tone.

 

[Scott_F]

Re: Another victory for the SD Pickup Booster!

Well, if you followed the 5F1 circuit, you are dealing with several issues at once. Firstly modern voltages. Depending on which power transformer you grabbed, you might have to adjust the bias resistor depending on how many volts are hitting the 6V6 (measure across pins 3 and 8). I use this page all time as a quick bias calculator. It's handy and if you go to the cathode bias section (3rd down I think) you can figure out if you need a different bias resistor. The amp might just be biased cold as heck and you're not hearing the love.

http://www.tedweber.com/webervst/tubes1/calcbias.htm

Also, unless you are running a NOS 5Y3, the "modern" versions are normally hotter. A proper copper cap for a 5Y3 might be closer than modern, but I've just never been a big fan of copper caps.

Next, the schematic of the 5F1 shows a 12AX7 in V1.

http://www.thevintagesound.com/ffg/schem/champ_5f1_layout.gif

If you put a 12AU7 in there, you're only at 20 something percent of the gain of the 12AX7. That's going to really underwhelm is my guess. You ran a 12AX7 in there and were not impressed. It's not the preamp tube. And if your rectifier voltage is off, then the voltage feeding the preamp tube is likely off as well. It's the sum of the parts.

I'd say measure the voltages on the 6V6GT and then run that calculator following the instructions on the Weber page. You'll likely need to adjust that cathode resistor and the amp will probably come to life for you. PM me off line if you want. Happy to help.

 

[leevc5]

Re: Another victory for the SD Pickup Booster!

Well, if you followed the 5F1 circuit, you are dealing with several issues at once. Firstly modern voltages. Depending on which power transformer you grabbed, you might have to adjust the bias resistor depending on how many volts are hitting the 6V6 (measure across pins 3 and 8). I use this page all time as a quick bias calculator. It's handy and if you go to the cathode bias section (3rd down I think) you can figure out if you need a different bias resistor. The amp might just be biased cold as heck and you're not hearing the love.

http://www.tedweber.com/webervst/tubes1/calcbias.htm

Also, unless you are running a NOS 5Y3, the "modern" versions are normally hotter. A proper copper cap for a 5Y3 might be closer than modern, but I've just never been a big fan of copper caps.

Next, the schematic of the 5F1 shows a 12AX7 in V1.

http://www.thevintagesound.com/ffg/schem/champ_5f1_layout.gif

If you put a 12AU7 in there, you're only at 20 something percent of the gain of the 12AX7. That's going to really underwhelm is my guess. You ran a 12AX7 in there and were not impressed. It's not the preamp tube. And if your rectifier voltage is off, then the voltage feeding the preamp tube is likely off as well. It's the sum of the parts.

I'd say measure the voltages on the 6V6GT and then run that calculator following the instructions on the Weber page. You'll likely need to adjust that cathode resistor and the amp will probably come to life for you. PM me off line if you want. Happy to help.

Thank you Scott_F! Followed the yellow brick road and found the love. The amp works beautifully now without the SD pup booster but sounds even better with it when playing my strat, with the Les Paul it sounds great all by itself.

Is there a way to put a power level pot in it so I can get the overdrive at lower volumes? You know something that would allow me to adjust the Wattage for say 1W thru the max of 5-6W.

 

[dystrust]

Re: Another victory for the SD Pickup Booster!

The truth is a good thing. The pickup booster performs two functions:

1. As a buffer. Guitars are high impedance outputs. The buffer effectively converts it to a low impedance output. This relieves the pickup of any "loading" effects of whatever the guitar is plugged into.

2. Flat amplifier. Simply allows you to boost the gain in order to overdrive the input to an amp or compressor. The latter being one of my favorite things to do.

Enjoy. I love mine too.

Hey Artie,
I remember seeing you mention that the original Pickup Booster can be changed from 470K to 1M input impedance by changing a resistor. Do you know which one I'd need to swap, and what the new value needs to be?

Thanks.

 

[Scott_F]

Re: Another victory for the SD Pickup Booster!

Thank you Scott_F! Followed the yellow brick road and found the love. The amp works beautifully now without the SD pup booster but sounds even better with it when playing my strat, with the Les Paul it sounds great all by itself.

Is there a way to put a power level pot in it so I can get the overdrive at lower volumes? You know something that would allow me to adjust the Wattage for say 1W thru the max of 5-6W.

So what did you do to fix it?

 

[Mincer]

Re: Another victory for the SD Pickup Booster!

Well, I am happy the Pickup Booster worked, but that should be a rockin' amp on its own.

 

[leevc5]

Re: Another victory for the SD Pickup Booster!

So what did you do to fix it?

All I did was replace R8 470 Ohm res at pin 8 with a 136.5 Ohm res.

 

[Scott_F]

Re: Another victory for the SD Pickup Booster!

Excellent work.

 

[GilmourD]

Re: Another victory for the SD Pickup Booster!

Why not a 12AY7?
12AU7 is lot lower in gain.

Glad you got it working!

That's what I was thinking, too.

Imagine how much better it'll sound with a 12AY7 AND​ the booster?

EDIT: For some reason the whole thread didn't load for me before I replied... Weird. I see you fixed it.

 

[GilmourD]

Re: Another victory for the SD Pickup Booster!

All I did was replace R8 470 Ohm res at pin 8 with a 136.5 Ohm res.

So, you changed the bias point on V1B, lowering the gain. Interesting since the actual Fender schematic calls for a 1500 ohm resistor.