Used Fender Frontman 15g into a Fender Champ?

[DJayhawk]

I have a damaged Fender Frontman 15g, and I'd like to build a Fender Champ style amp out of it. Does anyone have a tips for a good starting place?

 

I've been looking at the kits available, andI'd like to have the panel in front like it currently is in the 15g where can I get a chasis that has the dimensions of the current one with enough room for the 5F1 circuit? Will there be any usable parts from the 15g or pretty much just the cabinet?

 

Also does anyone have any write-ups of similar projects bookmarked that I could refer to?

 

I'm sure I'll have more questions as I move forward.

 

Thanks

 

PS: Mods-If this needs to be moved to the Amp section please feel free, I wasn't sure how to classify it.

[isaac42]

Seems appropriate to me. Good luck.

[WRGKMC]

So you're basically going to use the cab and speaker only or are you going to try to use the chassis as well?

 

If you build a transistor version of a champ I think you'll be OK. If you're figuring on a tube version I dont know If you'll have the space for ventallation and getting tubes fit in that space. Maybe if the tubes face the rear, I dont know. From what I remember the frontmans are pretty small. Dont know if the small speaker can handel the champ power either. I know thay make a 10W chanp, but thats tube power. It could cause a transistor amps speaker to fart out badly on the bass end. All things to think about before proceeding.

[DJayhawk]

 

So you're basically going to use the cab and speaker only or are you going to try to use the chassis as well? If you build a transistor version of a champ I think you'll be OK. If you're figuring on a tube version I dont know If you'll have the space for ventallation and getting tubes fit in that space. Maybe if the tubes face the rear, I dont know. From what I remember the frontmans are pretty small. Dont know if the small speaker can handel the champ power either. I know thay make a 10W chanp, but thats tube power. It could cause a transistor amps speaker to fart out badly on the bass end. All things to think about before proceeding.

 

 

No I was planning on building a tube version. I too doubt the speaker will handle the power so I will probably upgrade it.

 

I'd like to use the chassis because the cab has angle in it at the top where the controls for the 15g were. So my tentative plan is to have the tubes on the bottom side of the chassis and the board on the top. The tubes will be facing downward behind the speaker. Is it ok for the tubes to face downward?

 

As far as the ventilation there are two holes in the front face of the amp and i could easily leave the back plate off or modify it greatly to help with the air flow.

 

I'm still trying to plan this and find out if it's even doable, so any comments are greatly appreciated.

 

Thanks

[SomeoneYouKnew]

Will there be any usable parts from the 15g or pretty much just the cabinet?

Not much more than the line cord and the power switch. It would make sense to reuse the chassis. The dimensions fit the cabinet nicely. But you will have a {censored} ton of extra holes in the front and you will have a bit of work to do on the bottom side where you'll mount the tube sockets. Nothing that can't be handled.

[DJayhawk]

Thanks Someoneyouknow!

 

Good point about the speaker.

 

Thanks for the tip about modifying the back panel.

 

As far as all the holes in the front panel I was hoping to find a piece of sheet metal off the Jobsite and rivet it to the old one, then re-drill for the actual holes I do need.

 

Is it suggested to buy a preprinted board or just use a blank one?

[SomeoneYouKnew]

For an amp this simple, I think a blank board with no copper, then install turrets or eyelets for junction points would be a good choice.

 

 

The circuit in the picture is more complicated than the 5F1 you're talking about building. But you get an idea of how it's done.

[DJayhawk]

I've been trying to figure out if I can use the transformer from my 15g for this build but I have no idea what type of transformer or what the secondary is for it.

 

Anyone have any tips for figuring this out?

 

Here is the link to the 15g schematic if that will help: http://www.schematicx.com/schematic/fender-frontman-15g-15r-guitar-amplifier-schematic/

[SomeoneYouKnew]

The transformer from your frontman will be of no use to you in building a champ. The secondary is 33V with a center tap (16.5 - 0 - 16.5).

 

For a champ you need 3 secondaries. a 5V for the filament of the rectifier, a 6V for all the other heaters, and a 600V with center tap for the B+ (300 - 0 - 300)

[DJayhawk]

Thanks SYK, I now see where you read that on the 15g, but as far as the 5f1 schematic I only see the 6.3V to the filaments how did you know what the other voltages need to be?

 

I am by far no schematic reading expert, but I'm trying to get better

[Casey4s]

I am not sure what the size of the Frontman chassis is, but a Champ/Princeton circuit will fit easily in a 13x5 chassis.

[DJayhawk]

 

I am not sure what the size of the Frontman chassis is, but a Champ/Princeton circuit will fit easily in a 13x5 chassis.

 

 

This might be a dumb question but is the Champ Princeton different from the Champ 5f1 I was planning on building?

 

My chassis is 11 5/8" l x 4 1/2" w

 

I thought the 5f1 board was only 2" x 6" so I was thinking it would fit easily in my chassis, with the transformers, and tubes mounted to the underside of the chassis.

[Casey4s]

Sorry, the 5F1 Champ and 5F2 Princeton is essentially the same amp but with a tone control on the 5F2. I always build a 5F1 with a tone control and a switch to by pass the tone control if you want more of a raw Champ sound. Yeah, your turret board should fit inside OK.

[Belva]

This sounds like a good project for a noob like me. I'm bumping.

[SomeoneYouKnew]

Thanks SYK, I now see where you read that on the 15g, but as far as the 5f1 schematic I only see the 6.3V to the filaments how did you know what the other voltages need to be? I am by far no schematic reading expert, but I'm trying to get better

the 5Y3 rectifier needs a 5V filament winding.

 

I was making a rough estimate of 300 -0 -300 VAC for winding that feed the B+ supply. It looks like 285 -0 - 285 should get you the 305V dc for this circuit.

 

DC output of a full wave center tapped supply will be about 1.414 times the AC voltage across one leg of the transformer, but there is about a 90~100V drop across the 5Y3.

[DJayhawk]

Has anyone had any success using transformers from Triode? I found a bundle for the PT and OT which includes a choke that I do not think I need for my 5F1. It's for sale at Performance Guitar for $74.95 http://www.premierguitar.com/Gear/Amps/Amp_Parts/838321/Transformer_bundle_for_5F1_Fender_Champ_or_5F2_Princeton.aspx

 

I've heard that people can get in trouble when they order stuff from multiple suppliers that shipping cost's eat up any savings that may have been available.

 

Any other suggestions on where to get decent but reasonable priced transformers and possible other parts that I'm going to need?

 

Thanks

[Casey4s]

 

Has anyone had any success using transformers from Triode? I found a bundle for the PT and OT which includes a choke that I do not think I need for my 5F1. It's for sale at Performance Guitar for $74.95 http://www.premierguitar.com/Gear/Amps/Amp_Parts/838321/Transformer_bundle_for_5F1_Fender_Champ_or_5F2_Princeton.aspx I've heard that people can get in trouble when they order stuff from multiple suppliers that shipping cost's eat up any savings that may have been available. Any other suggestions on where to get decent but reasonable priced transformers and possible other parts that I'm going to need? Thanks

 

 

Although I can't say I ever bought any trannies there I have delt with Ned for years and they are straight up folks. I would be willing to bet that if he is selling them they are good stuff.

 

JMHO

[FranklinWalker]

i think it can work

[Casey4s]

Actually now that I think about it I did in fact buy a set of Transformers sone years ago but I don't remember if it ws for a 5E3 or for a 5F6A. But never any trouble an hi quality iron. A good transformer set is the heart of a tube amp.... go big if you can.