Stoj
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- Oct 6, 2006
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Yep Watto makes outatnding Amps, Here's my Splitty :dude: :salude
1947 Dual Professional information
- Thread starter Andrew Andrade
- Start date
Andrew Andrade
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- Joined
- Jul 10, 2002
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- 23
I didn't know that Watto made amps. That is one fine looking amp you have Stoj.
As for my amp, I did get all the correct values from his schematic. The Old Dual Pro now has some new Jupiter caps (same value as Red Astrons) and it sounds great.
Still trying to figure out the interactive volume and tone controls.
As for my amp, I did get all the correct values from his schematic. The Old Dual Pro now has some new Jupiter caps (same value as Red Astrons) and it sounds great.
Still trying to figure out the interactive volume and tone controls.
Stoj
Active member
- Joined
- Oct 6, 2006
- Messages
- 3,514
Thanks Andrew,
Watto is no longer making amps (for the time being anyway) as his day job has gotten really busy for him.
Shoot him an email, he knows these amps inside out :salude
Watto is no longer making amps (for the time being anyway) as his day job has gotten really busy for him.
Shoot him an email, he knows these amps inside out :salude
Hi All,
It's been a while since I've been here. I hope everyone is well.
Andrew contacted me in regards to his Dual Pro resto, He seems to have it up and running which is great.
I have owned (and since sold) quite a few of these early Fender beauties, A Dual Pro, a very early one with the Choke and single Field coil OT (Yes Efk they did exist but only 2 or 3 were made AFAIK , I also had one with 2 standard OT's mounted on each speaker) , both original, Leo was trying many things in 46/47 so his amps weren't all the same, I'm guessing it was what he could get his hands on at the time, especially considering the timeline of the era, just after WWII where everyone was still recovering from it .
The Dual Pro and the Pro "Woodie" were basically the same amp, they did have a few different component values , (the choke was in the DP for only a very few amps) but they were basically the same, It's also interesting to note that the Gibson GA40 of the time period was the same circuit as well, All out of the same Western Electric handbook I'd say (I have yet to find it in that book so that's just a guess) . So I decided I would draw the schematic and add voltages taken from my personal amps , then add the differences to that schematic to include the Woodie Pro and the GA40. That way you can see the differences AND similarities between the 3 amps.
Here is a layout of my late 46 Dual Pro (it's not exactly the same as the schem below - Leo chopped and changed back then)
And here's the Schematic with all 3 amps on it, The schem is Dual Pro, the differences are marked in different colours, see the legend for details , voltages were taken from my 47 Dual Pro with 2 OT's
If you have any questions, I'm glad to help
In regard to the tweed cloth used on the Dual Pro's , Leo had just acquired a large batch of 10 inch speakers, Basically the whole reason the DP was designed , So he went with a modified Woodie Pro circuit and as he didn't have the resources at the time to build the cabinets, He out sourced them to a local manufacturer ( well documented in the book by Richard Smith) They covered them in a tweed/linen that was at hand at the time , and the reason was to cover up the finger joints on the cab the Leo apparently didn't like. I do have the name of the small business who built these cabs but it's in my archive boxes and would take too long to find, I do know they they are no longer in business , from memory they closed down in the mid to late 50's
The tweed that is best known for the Fender Super was from 47 on , when Leo started building the cabs in house after copying the original cab.
My nerdy obsession with these amps went so far as to find a fabric supplier in the Fullerton area who closed down around 2008. They were in business from the early 40's, I saw they were selling all their stock and the add read that it dated back to to 40's, I asked if they had any tweed from the 40's and the informed me they had a roll of "linen" suitcase covering from 1946, 200 yards to be exact. I was able to get enough to do approx 10 split front cabs , I still have it . From all the photos and research I done (Very OCD hahaha) it's not exact cloth that was used by Fender and the outsourced business, but is so close that it can very easily be used to restore a Dual Pro
Andrew I see you've had your cab redone in modern tweed, I wish you'd contacted me before then as I could've sent you some 40's cloth
Back to the circuit , I personally think the 6SJ7 preamp tube is one of the nicest there is, I love the sound of a nice Pentode preamp, the only problem I found with the Dual Pro was the biasing of the output tubes, I feel the 10f/120 ohm resistor on the 6L6's doesn't give enough headroom, they are biased way too hot, (I'm guessing he did this because of the 2 OT's ) I prefer the Woodie Pro values (and all the later tweeds as well) of 25uf//250 ohms . to me that's the perfect setup. I also don't like the choke in the power section, It was on;y used very briefly on the DP and having owned one I could hear why Leo dropped it pretty quick. Again, the Woodie Pro values are much nicer tone wise.
These were/are great amps, I love the rawness of the circuit and when you find the sweet spot they just sing .
Great thread guys
regards
Watto
It's been a while since I've been here. I hope everyone is well.
Andrew contacted me in regards to his Dual Pro resto, He seems to have it up and running which is great.
I have owned (and since sold) quite a few of these early Fender beauties, A Dual Pro, a very early one with the Choke and single Field coil OT (Yes Efk they did exist but only 2 or 3 were made AFAIK , I also had one with 2 standard OT's mounted on each speaker) , both original, Leo was trying many things in 46/47 so his amps weren't all the same, I'm guessing it was what he could get his hands on at the time, especially considering the timeline of the era, just after WWII where everyone was still recovering from it .
The Dual Pro and the Pro "Woodie" were basically the same amp, they did have a few different component values , (the choke was in the DP for only a very few amps) but they were basically the same, It's also interesting to note that the Gibson GA40 of the time period was the same circuit as well, All out of the same Western Electric handbook I'd say (I have yet to find it in that book so that's just a guess) . So I decided I would draw the schematic and add voltages taken from my personal amps , then add the differences to that schematic to include the Woodie Pro and the GA40. That way you can see the differences AND similarities between the 3 amps.
Here is a layout of my late 46 Dual Pro (it's not exactly the same as the schem below - Leo chopped and changed back then)
And here's the Schematic with all 3 amps on it, The schem is Dual Pro, the differences are marked in different colours, see the legend for details , voltages were taken from my 47 Dual Pro with 2 OT's
If you have any questions, I'm glad to help
In regard to the tweed cloth used on the Dual Pro's , Leo had just acquired a large batch of 10 inch speakers, Basically the whole reason the DP was designed , So he went with a modified Woodie Pro circuit and as he didn't have the resources at the time to build the cabinets, He out sourced them to a local manufacturer ( well documented in the book by Richard Smith) They covered them in a tweed/linen that was at hand at the time , and the reason was to cover up the finger joints on the cab the Leo apparently didn't like. I do have the name of the small business who built these cabs but it's in my archive boxes and would take too long to find, I do know they they are no longer in business , from memory they closed down in the mid to late 50's
The tweed that is best known for the Fender Super was from 47 on , when Leo started building the cabs in house after copying the original cab.
My nerdy obsession with these amps went so far as to find a fabric supplier in the Fullerton area who closed down around 2008. They were in business from the early 40's, I saw they were selling all their stock and the add read that it dated back to to 40's, I asked if they had any tweed from the 40's and the informed me they had a roll of "linen" suitcase covering from 1946, 200 yards to be exact. I was able to get enough to do approx 10 split front cabs , I still have it . From all the photos and research I done (Very OCD hahaha) it's not exact cloth that was used by Fender and the outsourced business, but is so close that it can very easily be used to restore a Dual Pro
Andrew I see you've had your cab redone in modern tweed, I wish you'd contacted me before then as I could've sent you some 40's cloth
Back to the circuit , I personally think the 6SJ7 preamp tube is one of the nicest there is, I love the sound of a nice Pentode preamp, the only problem I found with the Dual Pro was the biasing of the output tubes, I feel the 10f/120 ohm resistor on the 6L6's doesn't give enough headroom, they are biased way too hot, (I'm guessing he did this because of the 2 OT's ) I prefer the Woodie Pro values (and all the later tweeds as well) of 25uf//250 ohms . to me that's the perfect setup. I also don't like the choke in the power section, It was on;y used very briefly on the DP and having owned one I could hear why Leo dropped it pretty quick. Again, the Woodie Pro values are much nicer tone wise.
These were/are great amps, I love the rawness of the circuit and when you find the sweet spot they just sing .
Great thread guys
regards
Watto
Last edited:
MapleFlame
Well-known member
- Joined
- Jul 3, 2005
- Messages
- 14,044
Hi All,
It's been a while since I've been here. I hope everyone is well.
Andrew contacted me in regards to his Dual Pro resto, He seems to have it up and running which is great.
I have owned (and since sold) quite a few of these early Fender beauties, A Dual Pro, a very early one with the Choke and single Field coil OT (Yes Efk they did exist but only 2 or 3 were made AFAIK , I also had one with 2 standard OT's mounted on each speaker) , both original, Leo was trying many things in 46/47 so his amps weren't all the same, I'm guessing it was what he could get his hands on at the time, especially considering the timeline of the era, just after WWII where everyone was still recovering from it .
The Dual Pro and the Pro "Woodie" were basically the same amp, they did have a few different component values , (the choke was in the DP for only a very few amps) but they were basically the same, It's also interesting to note that the Gibson GA40 of the time period was the same circuit as well, All out of the same Western Electric handbook I'd say (I have yet to find it in that book so that's just a guess) . So I decided I would draw the schematic and add voltages taken from my personal amps , then add the differences to that schematic to include the Woodie Pro and the GA40. That way you can see the differences AND similarities between the 3 amps.
Here is a layout of my late 46 Dual Pro (it's not exactly the same as the schem below - Leo chopped and changed back then)
And here's the Schematic with all 3 amps on it, The schem is Dual Pro, the differences are marked in different colours, see the legend for details , voltages were taken from my 47 Dual Pro with 2 OT's
If you have any questions, I'm glad to help
In regard to the tweed cloth used on the Dual Pro's , Leo had just acquired a large batch of 10 inch speakers, Basically the whole reason the DP was designed , So he went with a modified Woodie Pro circuit and as he didn't have the resources at the time to build the cabinets, He out sourced them to a local manufacturer ( well documented in the book by Richard Smith) They covered them in a tweed/linen that was at hand at the time , and the reason was to cover up the finger joints on the cab the Leo apparently didn't like. I do have the name of the small business who built these cabs but it's in my archive boxes and would take too long to find, I do know they they are no longer in business , from memory they closed down in the mid to late 50's
The tweed that is best known for the Fender Super was from 47 on , when Leo started building the cabs in house after copying the original cab.
My nerdy obsession with these amps went so far as to find a fabric supplier in the Fullerton area who closed down around 2008. They were in business from the early 40's, I saw they were selling all their stock and the add read that it dated back to to 40's, I asked if they had any tweed from the 40's and the informed me they had a roll of "linen" suitcase covering from 1946, 200 yards to be exact. I was able to get enough to do approx 10 split front cabs , I still have it . From all the photos and research I done (Very OCD hahaha) it's not exact cloth that was used by Fender and the outsourced business, but is so close that it can very easily be used to restore a Dual Pro
Andrew I see you've had your cab redone in modern tweed, I wish you'd contacted me before then as I could've sent you some 40's cloth
Back to the circuit , I personally think the 6SJ7 preamp tube is one of the nicest there is, I love the sound of a nice Pentode preamp, the only problem I found with the Dual Pro was the biasing of the output tubes, I feel the 10f/120 ohm resistor on the 6L6's doesn't give enough headroom, they are biased way too hot, (I'm guessing he did this because of the 2 OT's ) I prefer the Woodie Pro values (and all the later tweeds as well) of 25uf//250 ohms . to me that's the perfect setup. I also don't like the choke in the power section, It was on;y used very briefly on the DP and having owned one I could hear why Leo dropped it pretty quick. Again, the Woodie Pro values are much nicer tone wise.
These were/are great amps, I love the rawness of the circuit and when you find the sweet spot they just sing .
Great thread guys
regards
Watto
Fantastic information, thank you. :salude
Without seeing pictures I'd say transitional. Leo Fender was a stooge, he never threw anything out , my guess would be he ran out of Dual Pro chassis' and had already received his super chassis' order , had some leftover speakers and transformers etc , so they built a DP into a Super chassis. he got the Dual Pro badges from the 2 neck lap steel of the same name , he was a clever guy when it came to using the same parts for various applications
Did it run 6SJ7's or 6SC7's ? Did it have the input between the volume/tone pots which was DP only ? If you can remember all that I'd be able to give you more info
regards
Watto
Andrew Andrade
New member
- Joined
- Jul 10, 2002
- Messages
- 23
Watto:
Thanks for sharing your knowledge of this groundbreaking Fender amp and taking the time to help me with my amp. It is appreciated and I also want to thank those that contributed their information to the thread.
Thanks for sharing your knowledge of this groundbreaking Fender amp and taking the time to help me with my amp. It is appreciated and I also want to thank those that contributed their information to the thread.
D'Oh , yes scrooge
thunderbird_sprt
New member
- Joined
- Dec 29, 2018
- Messages
- 1
Just wondering if anybody has an accurate schematic of the 1947 Fender Dual Professional? The previous linked schematics have been taken down.
Thanks
Thanks
aspen pitman had a bunch of schematics in his book, he owned one also. not sure but worth a try.
i have number 12. if i remember right it has differences from the later super v fronts.
the early ones also had a white ish covering
i heard the same 'white linen' was used in cesna airplanes for headliners in the forties. just a rumor of course!
White linen covered Dual professional. Obviously some changes to it, but the speakers with OT's on them is how they would come. one looks aftermarket or just changed. I was told the speaker magnets never held their magnetism very well and they are next to impossible to recharge. I'm still looking for one of these.
