I think a voltage divider is a good way to tame the gain without changing overall tone. But there are many others, the quickest is to remove the bypass caps at the cathode of the first stage.
I might take a trip to Toronto on Saturday, theres a few places I might be able to get some caps. It might be worth the trip as I could get "new" caps, save on shipping and time.
Perhaps it would be best to recap like you say, first, before changing too much.
I like lot's of gain, if the capacitors clean it up, I might take the grid resistor out or lower it.
I'm so excited.
Perhaps it would be best to recap like you say, first, before changing too much.
I like lot's of gain, if the capacitors clean it up, I might take the grid resistor out or lower it.
I'm so excited.
shipping
Newark is charging me $5.50 UPS shipping from NorthCarolina to INdiana. Triodeelectronics.com is near Chicago, if you buy a tube they charge $10 USPS shipping for a lot of fluffy packaging, but if there are no tubes and it will ride 1st class mail it is less. I pay $8 minimum UPS from Arizona to IN, tubesandmore.com. For american made parts (vishay sprague orange drop caps, big panasonic electrolytic caps) and mexican made parts (On semi, aerovox gold ceramic caps) there should be no import duty since all 3 countries are in NAFTA. All take debit cards for electronic orders. I can't drive to south downtown louisville to the electronics distributor for $5. But your car may get better milage. Note 1-10 uf caps up to 50v can be ceramic now instead of electrolytic, although J Curl discourages this.
Have fun. Electronics is more fun than Scrabble for me.
Newark is charging me $5.50 UPS shipping from NorthCarolina to INdiana. Triodeelectronics.com is near Chicago, if you buy a tube they charge $10 USPS shipping for a lot of fluffy packaging, but if there are no tubes and it will ride 1st class mail it is less. I pay $8 minimum UPS from Arizona to IN, tubesandmore.com. For american made parts (vishay sprague orange drop caps, big panasonic electrolytic caps) and mexican made parts (On semi, aerovox gold ceramic caps) there should be no import duty since all 3 countries are in NAFTA. All take debit cards for electronic orders. I can't drive to south downtown louisville to the electronics distributor for $5. But your car may get better milage. Note 1-10 uf caps up to 50v can be ceramic now instead of electrolytic, although J Curl discourages this.
Have fun. Electronics is more fun than Scrabble for me.
If it's not bypassd by a capacitor it will - bigger the resistor, lower the gain.
Thanks Nigel. TechnoBeaver, look at this thread about shipping from US to Canada- apparently they make up for the cheap prices I get at the border headed north. http://www.diyaudio.com/forums/lounge/164041-international-shipping-options-us.html
Pity you don't live in Emerson, Manitoba across from Pembina, Minnesota, you could start an electronics forwarding business. I understand Detroit/Windsor is a big bottleneck now like El Paso/Juarez.
Pity you don't live in Emerson, Manitoba across from Pembina, Minnesota, you could start an electronics forwarding business. I understand Detroit/Windsor is a big bottleneck now like El Paso/Juarez.
Best to start with this document. It is a single ended amp but it goes through the stages of a guitar amp and gives you an idea of what you should see voltage wise. If it makes sense a quick brush up of phase inverters and push pull output section is all you need.
http://ax84.com/p1/P1_Theory_Document.zip
How to design valve guitar amplifiers
Some Fender schematics. Princeton, Deluxe, and a few others use 6v6's.
http://www.ampwares.com/fender.asp
Gibson also has some and for a Marshall flavor a 6v6 plexi at
http://mhuss.com/Plexi6V6/index.html
http://ax84.com/p1/P1_Theory_Document.zip
How to design valve guitar amplifiers
Some Fender schematics. Princeton, Deluxe, and a few others use 6v6's.
http://www.ampwares.com/fender.asp
Gibson also has some and for a Marshall flavor a 6v6 plexi at
http://mhuss.com/Plexi6V6/index.html
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Thanks for the links, I was thinking of getting that book actually.
I never made it to the City, I kinda agree with Joe about the shipping. I will keep tinkering with the amp, then just try to get everything from one of those places.
I did however get some nice parts for the project this morning.
All this for $50 CAD 🙂
-Heathkit SB100 HAM (Some Mullards in there and just look at those dials.)
-Heathkit SB630 Console (a testing/ monitoring unit for the ham)
-Fisher Studio Standard CA-225D 60wpc amp
-a pair of AKAI SA-CA1 speakers.
-a modern little TV (works, for parts suitible for this project as recommened.)
-and a 200W fart cannon
It might be a shame to part out that HAM gear as it does hold some value to those guys. I might even use one of the enclosures. (originaly I was going to make one out of wood)
I have an assortment of the odd nice dial, but nothing like those. I also have those chessy ones that RatShack sells you for $5.99/pair. Heck I would have gave the guy $20 bucks just for the 16 dials.
Where to start, oh ya I forgot I wanted to remove the feedback from the OPT.
I never made it to the City, I kinda agree with Joe about the shipping. I will keep tinkering with the amp, then just try to get everything from one of those places.
I did however get some nice parts for the project this morning.
All this for $50 CAD 🙂
-Heathkit SB100 HAM (Some Mullards in there and just look at those dials.)
-Heathkit SB630 Console (a testing/ monitoring unit for the ham)
-Fisher Studio Standard CA-225D 60wpc amp
-a pair of AKAI SA-CA1 speakers.
-a modern little TV (works, for parts suitible for this project as recommened.)
-and a 200W fart cannon
It might be a shame to part out that HAM gear as it does hold some value to those guys. I might even use one of the enclosures. (originaly I was going to make one out of wood)
I have an assortment of the odd nice dial, but nothing like those. I also have those chessy ones that RatShack sells you for $5.99/pair. Heck I would have gave the guy $20 bucks just for the 16 dials.
Where to start, oh ya I forgot I wanted to remove the feedback from the OPT.
Attachments
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Turns out I already removed the feedback, it was something else. I do have a pair of suspect caps to replace.
Pretty quiet around here today.
It was I good day. Below are a couple of pics of the coupling caps I swapped out of the inverter stage. I replaced the greasy "Plastiseal" .047 600V, with some Sangamo .1 600V. Again, I will be getting new caps when I'm done tinkering.
I also had the wrong 5Y3 in there, I put the original 5-pin back in.
I rolled a couple of 12AT7's that I salvaged from the Heathkit Ham. The 12AT7's sounded nice, a little more open. They really did not lack very much distortion vs the 12AX7.
Very nice. This machine is turning out good.
It was I good day. Below are a couple of pics of the coupling caps I swapped out of the inverter stage. I replaced the greasy "Plastiseal" .047 600V, with some Sangamo .1 600V. Again, I will be getting new caps when I'm done tinkering.
I also had the wrong 5Y3 in there, I put the original 5-pin back in.
I rolled a couple of 12AT7's that I salvaged from the Heathkit Ham. The 12AT7's sounded nice, a little more open. They really did not lack very much distortion vs the 12AX7.
Very nice. This machine is turning out good.
Attachments
More parts for the amp project.
I thought I would go back to where I got the other junk, as I firqured there may be a power supply around for the HAM Radio pictured above. I thought it would have a nice transformer for a guitar amp or other project.
Well I found it. I got that and the rest of this for $10 🙂.
I might be able to use the power supply as it is setup, or keep it for bench testing. Have to do some research.
Lot's of nice hardware, a very handy book, some tubes, volts and amp meters, few bags of hardware etc. very cool.
Some poor old guys hobby ended up in some boxes.🙁
Oh well I can make use of some of it and marvel at the rest.
I am going to go back for sure. There are many more tube related books and possibly more loose tubes and parts.
It's in the an area the owner will not let the public access, so it's kinda hard to get a good snoop going. (damaged roof above)
I rolled in there this morning and the old fella was just leaving, so I got to deal with his son, nice guy too. He let's me get a little closer to have a dig.
I love this hobby.
I thought I would go back to where I got the other junk, as I firqured there may be a power supply around for the HAM Radio pictured above. I thought it would have a nice transformer for a guitar amp or other project.
Well I found it. I got that and the rest of this for $10 🙂.
I might be able to use the power supply as it is setup, or keep it for bench testing. Have to do some research.
Lot's of nice hardware, a very handy book, some tubes, volts and amp meters, few bags of hardware etc. very cool.
Some poor old guys hobby ended up in some boxes.🙁
Oh well I can make use of some of it and marvel at the rest.
I am going to go back for sure. There are many more tube related books and possibly more loose tubes and parts.
It's in the an area the owner will not let the public access, so it's kinda hard to get a good snoop going. (damaged roof above)
I rolled in there this morning and the old fella was just leaving, so I got to deal with his son, nice guy too. He let's me get a little closer to have a dig.
I love this hobby.
Attachments
Well I think I am going to close the thread, maybe move it somewhere else, due to lack of interest.
Thank you very much, to all those that contributed.
Thank you very much, to all those that contributed.
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