Plexi 50 combo.. help me make good choices

[Opry Audio]

Hey y’all,

I would very much like to build another plexi since the last one came out great. I want to build it into a combo using a bassman chassis and a 1x12 bassman style cabinet. Any advice on iron that would be small enough to put in a combo chassis and still have the Marshally tone we want? My intuition is to drill additional holes to mount the 50 / 50 can caps assuming they are shorter than the iron and provide enough clearance as well. Has anyone tried this with good results?

[bmccowan]

A lot of views, but no replies. I suspect its because folks are confused (me too) as to what you want to do. So, I assume that you are wanting to use a 5F6 style chassis and cabinet with 1-12" speaker. If so, I am not seeing a clearance issue. Prior to the 4x10 amps the bassman had a 15" speaker in the same size cabinet, as did some other tweed models. I don't think the plexi iron is physically much larger than the bassman iron and you should be able to get either laydown or upright style, and modern cap cans are not very tall. So I would choose the iron that suits the power needs first and then make sure that the cab you build/buy will fit. The Fender Amp Field Guide has dimensions of all the cabinets - that might help.
If this is not getting at what you are asking - please clarify.

[pdf64]

Dunno what exactly folk mean when referring to ‘plexi’ 
There’s more to an amp than the front panel!
My understanding is that ‘plexi’ refers to more of an era thing rather than a specific model or circuit but, as per the OP, that doesn’t tend to be how the term gets used.
I guess that given context of the thread title, it may mean a 1987 or 2204?
Sorry Opry, I’m not meaning to pick on you 
Regarding iron, if considering classictone, then best to order asap 

[shooter]

here's how I "define" plexi;
2 channels with one input mixed at the output of the 2 channels
(can include individual CH Vol & TS)


plastic front panel optional 

[2deaf]

There seems to be a high correlation between the word "plexi" and anything with a 5F6-A pre-amp topology.

[Opry Audio]

Sorry guys maybe I should have been more clear in my post. What I’m specifically referring to is the Hoffman Plexi 50. Whatever model that is based off of, a 5F6 seems like a good candidate for building into a combo. Someone asked me to build another one but wants it in a smaller package. I will check out the fender amp field guide! To be quite honest I’m a little bit lacking in chassis skills when it comes to drilling, widening holes for lay down transformers, etc.

I just built a Hoffman plexi into a JMP and those transformers were pretty big, the amp sounded amazing but that might be to the credit of those transformers somewhat.

[Willabe]

Regarding iron, if considering classictone, then best to order asap 

What do you mean?

Is classictone going out of business?   

[bmccowan]

In that case I think you are right to be thinking of the 5f6 chassis. Lots of them out there. And if it were me, I'd use a PT that fits that chassis and tape off the 5V leads if you don't want them, and then choose whatever OT you want. That would be minimal hole drilling. Again, if it were me, I would not downsize the cabinet from the 5F6, I'd just make/use a 12" speaker baffle. That way changing to a 15 or 4-10s down the road is possible. I built a 5E5A Pro that way. 15" speaker and its a Pro, 2x10 and its a 5F4 Super. Eventually I decided on the 15 and used the 10s in another project.
I think your idea is cool. But! I would also suggest thinking about the Plexi 6V6 which is a great sounding amp and a well documented project.
And I am also wondering about the Classictone comment. Are they just slow these days? Covid related? Although their documentation is lacking (as in often wrong) I like their transformers and we need U.S. made products.

[pdf64]

Might just be me, but I find tweed type chassis horribly cramped, turning a build into more of a struggle than I prefer; Marshall type chassis are far more civilised 

Regarding iron, if considering classictone, then best to order asap 

What do you mean?

Is classictone going out of business?   

Unfortunately, that’s the word on the grapevine.

[Willabe]

Unfortunately, that’s the word on the grapevine.

They've been in business for 75 years, sad.

[bmccowan]

I did a search to see if they were for sale, and could find nothing. It does not seem like they would just close up. But of course they could be working quietly on a deal. I'd hate to see them disappear.

[Opry Audio]

Sorry to hear about classictone too. Thanks for the good advice guys. He changed his mind and wants me to build a Princeton reverb instead. Should be pretty straight forward. But I'm also excited to put some effort into the looks, my past ones have looked like other amps.

I have a 90 degree angle front princeton chassis, and I think I'll find someone to build a princeton cabinet without the angled top and with a TV front. Has anyone worked with TRM or guitarcabinets direct? AND Allen amps just got back to me about TP25's being back in stock. So, it was meant to be I suppose. Will do another hoffman plexi soon.

[steveo7868]

I am so sad to hear about classictone, are you sure about that, I just placed a pretty big order
so sad they work so well, I guess I can find others.. bummer

[brewdude]

I had TRM build me a custom tubes up, 2x8” 3D style (w/side vents) combo out of pine.  I had it delivered unfinished.  I gave it fire roasted finish.  It turned out great. 

[pdf64]

I am so sad to hear about classictone, are you sure about that, I just placed a pretty big order
so sad they work so well, I guess I can find others.. bummer

I'm not usually a good source for gossip but it popped up at MEF last week, and I thought it was useful info for anyone thinking of buying transformers in the near future; see this clip from Dave Friedman

=4249
Then Andy Fuchs confirmed it at TGP but indicated there may be some hope yet https://www.thegearpage.net/board/index ... t-31329850
There seems a good likelihood you'll get your stuff.

[steveo7868]

Hey Thanks for the info, yeah I am waiting on orders from Tube Depot and Triode,
really tapped at the moment or would buy more, but really just fender and marshall replacements
so Heyboer is an option, I think Mojo uses them, also Allen Amps has nice stuff
still a shock to hear, hope someone can save the operation at classictone

[steveo7868]

I am so sad to hear about classictone, are you sure about that, I just placed a pretty big order
so sad they work so well, I guess I can find others.. bummer

Then Andy Fuchs confirmed it at TGP but indicated there may be some hope yet https://www.thegearpage.net/board/index ... t-31329850
There seems a good likelihood you'll get your stuff.

Could you repost that link to TGP,? I could not get this one to work

[pdf64]

Could you repost that link to TGP,? I could not get this one to work

Sorry, I should've checked it  https://www.thegearpage.net/board/index.php?threads/thoughts-on-classictone-transformers.1193356/#post-31329850

[steveo7868]

Hey Thanks again, well I feel better about things, I think I sourced everything I need from Heyboer,
not to mention I am stocked up for a while now, lets see what happens!! 
Cheers All