i have a few Bogen Challengers, and recently i stripped one of the old CHB100s down to the chassis with hopes of cleaning it up and building a silvertone 1484 type circuit. i plan on just building the 2nd channel without reverb or tremolo in order to keep it nice and simple. i'll most likely keep it at 50w because i don't really like how these bogen transformers work with the 100w versions. they seem rather under spec'd.
i've begun drawing up layout , i have the schematic started in eagle, and the preamp section is basically done. i've followed the schematic and layed it out on eyelet board. i have done many stompbox layouts in the past, so i can handle the preamp section- i think. should i be trying to bunch everything together so that there is the least amount of separation between parts going to gr, parts going to B+, etc, or is it ok to just follow the schematic and run a few jumpers? should all of the filter caps go on a separate board, or are there some that can should be on the preamp board? i guess i really need to study up on some other layouts. are there any layouts of note that you guys could suggest that use proper methods? i've posted what i have so far, i'll repost when i get it sorted a bit more.
i have basic knowledge of tube amps, and have a decent amount of stompbox and electronic experience, but this will be my first full tube amp build. is there anything i should know when working with these bogen trannies? and how can i be sure i have them sorted properly? will the basic bogen power topology be ok for the build? should i just follow the chb100 schematic for the power section, and follow silvertone for the rest? anything you guys can think to add would be greatly appreciated.
btw, this is a great forum! i hope to extend my internet travels over to these parts more often in the future. many thanks!
i attached the 1484 schemo and what i believe is the correct chb100 schematic.
building a SIlvertone 1484 onto a Bogen chassis/trafos
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building a SIlvertone 1484 onto a Bogen chassis/trafos
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Last edited by RNFR on Sun Apr 18, 2010 4:50 pm, edited 1 time in total.
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
See if you can make a layout with all the ground connections on one side, the B+ connections on one side, and the tube socket connections on one side. OK, I know that's 3 sides. 
Pick 2 for one side, probably B+ and ground.
Pick 2 for one side, probably B+ and ground.
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
Well you certainly chose a complex amp for your first project.
Hope it works out well for you.
About the only thing I can offer is to make sure that you get a chassis that is long enough for all the components.
Nothing worse than a cramped chassis which will lead to stability problems.
Something I have done in the past when doing my own layout was to find a comparable amp that already has the boards or layout done then copy it and make changes where necessary.
Hope it works out well for you.
About the only thing I can offer is to make sure that you get a chassis that is long enough for all the components.
Nothing worse than a cramped chassis which will lead to stability problems.
Something I have done in the past when doing my own layout was to find a comparable amp that already has the boards or layout done then copy it and make changes where necessary.
Last edited by Structo on Sun Apr 18, 2010 4:54 pm, edited 1 time in total.
Tom
Don't let that smoke out!
Don't let that smoke out!
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
that's kind of what i figured would be best once i got going. it shouldn't be that hard to do some rearranging now that i've already got most of it worked out. thanks for the tip.Phil_S wrote:See if you can make a layout with all the ground connections on one side, the B+ connections on one side, and the tube socket connections on one side. OK, I know that's 3 sides.
edit-
the only problem is that there are only 9 connections for ground and B+. the rest are to tubes or pots. i'm not sure it's possible. i guess i'll just have to try and get them as close as possible.
Last edited by RNFR on Sun Apr 18, 2010 5:06 pm, edited 2 times in total.
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
i've got a good handle on audio circuits as i've been building and designing my own SS stompbox circuits for the last 4 or so years, so i think i should be able to handle that side of the equation with no problems. it's really the high voltage layout techniques and power problems that i need to study up on. i've been putting off building an amp for a while, and i thought this would be a cheap and easy way to get started as i already have most of the parts in my shop.Structo wrote:Well you certainly chose a complex amp for your first project.
Hope it works out well for you.
About the only thing I can offer is to make sure that you get a chassis that is long enough for all the components.
Nothing worse than a cramped chassis which will lead to stability problems.
the bogen chassis isn't the largest, but i'm hoping it should be ok if only do one channel.
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
Well typically any wires carrying AC are twisted to help cancel noise.
The DC high voltage wires are routed as direct as possible while avoiding close proximity to AC wires.
Low voltage signal wiring is kept clear of other wires and if they have to cross paths then do it at 90 degrees.
You just have to study amp pictures to see proper lead dress techniques.
Do not look at Fender Silverface amps........they are terrible in the lead dress.
Heater wiring is usually done one of two ways.
The Fender way is overhead of the sockets and the Marshall way is to keep them on the chassis floor in the back corner of the chassis.
Just depends how your amp is laid out whether one will work better than the other.
The DC high voltage wires are routed as direct as possible while avoiding close proximity to AC wires.
Low voltage signal wiring is kept clear of other wires and if they have to cross paths then do it at 90 degrees.
You just have to study amp pictures to see proper lead dress techniques.
Do not look at Fender Silverface amps........they are terrible in the lead dress.
Heater wiring is usually done one of two ways.
The Fender way is overhead of the sockets and the Marshall way is to keep them on the chassis floor in the back corner of the chassis.
Just depends how your amp is laid out whether one will work better than the other.
Tom
Don't let that smoke out!
Don't let that smoke out!
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
Use a buss type ground, like you see here:RNFR wrote:the only problem is that there are only 9 connections for ground and B+. the rest are to tubes or pots. i'm not sure it's possible. i guess i'll just have to try and get them as close as possible.
http://home.comcast.net/~psymonds/TMB18W.htm
look for the naked copper wire along the side of the board.
Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
This schematic probably doesn't help much but I thought I would post it anyway, didn't find a layout to go with it. This is from Hoffman SCH files.
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Re: building a SIlvertone 1484 onto a Bogen chassis/trafos
thanks a lot guys! i'll try and get a chance to look this stuff over in the next couple of days, and get back when i have a chance.
1484 schematic
I drew that schematic from the Hoffman forum SCH files. Double check it with the one at Schematic Heaven. I am NOT certain it was drawn correctly so check for errors.
With respect, 10thtx
With respect, 10thtx