Gutar Amplifier Project Thoughts

[Shuie]

Here is some good technical info on the 5E3:

https://robrobinette.com/How_The_5E3_Deluxe_Works.htm

The Weber site has an excel workbook you can download with BOMs for almost every '50s & '60s clone. The part numbers are all for the stuff they sell, but it's a decent starting point for a scratch build.

[jmp81sc]

Look into Boothill amps. He is a small shop out of Florida with great prices and good parts.

I have built two of his amps, a 50 watt 5F6A Tweed Bassman and a 5F2A Tweed Princeton.
For your needs the Tweed Champ 5F1 or Princeton 5F2A with a 10 or 12 inch speaker would work great. They are only 5 watt amps but that is louder than most people think when at home. The 5E3 deluxe is also a good choice and not much harder to build.

I like the Telecaster forum DIY section, tons of info and support there with very helpful posters.

Be careful it is addicting.
John

[Ayles]

Forgot to mention two great books on building amplifiers.

Building valve amplifiers and valve amplifiers. Both are by Morgan Jones. Not guitar specific but the techniques on chassis construction and all the math involved im sure is still applicable.

[Superman]

I play bass, and I prefer tube amps. For bass, clean headroom is what we typically want. My head is 300 tube watts. 35 years old. Best bass tone on the planet, I think.

Overall, the best guitar amp I have shared a stage with was and old (seventies, I think) MusicMan 112 combo with two output tubes. I think it was about 25 watts. This thing was smaller than most suitcases. Had reverb and distortion. It certainly got the job done. I am glad you guys are not talking about hundred-watt heads and multiple 12" speakers. Most of your favorite guitar tones (zeppelin, Queen, Who, Stones, etc.) were recorded using a remarkably small amp.

[ledhedsymbols]

OK, change of plans... I dug through my salvage boxes in my radio shop because I recall scrapping an old Sentinel turntable with a Maggie amp in it, and I thought that it used the same tubes (12AX7, 6V6, and 5U3) as the amps I was looking at. Just my luck! It's a PP 6V6 amp with a single 12AX7 pre and a 5Y3 rectumfryer. It also has a PT and OT that will do nicely too, plus a chassis. Looks like I'll be building something in the existing chassis and running to remote switches on a panel. Haven't figured out how I'm going to do it exactly, but this shouldn't be hard at all. The speakers are nothing special, but the OT is good for 8 ohms and I've got choices galore with that.

The tubes all check out strong, now I'll just decide which circuit I want to start with. Fun Fun Fun!

[ledhedsymbols]

[Superman]

As an expert, I can tell you that chassis is.....dirty.

My "Magnavox" labeled tubes are, for the most part, Sylvania. It looks like you will not have much to do. How about....plug it in and see if it works?

[ledhedsymbols]

Originally Posted by Superman

As an expert, I can tell you that chassis is.....dirty.

My "Magnavox" labeled tubes are, for the most part, Sylvania. It looks like you will not have much to do. How about....plug it in and see if it works?

I little work to do first. I need to swap out the electrolytics at a minimum and give it a good once over. Anyone know if the old Maggie speakers are any good?

[jmp81sc]

Looks like you have a good start there. I'm out of my league hear, but is this a single ended Class A design? Seems like with two 6V6's you need another 12AX7 for phase inverter duties for Class A/B.

Looks perfect for either a 5E3 Deluxe with the addition of a 12AX7 or a 5F1/5F2A with one 6V6.

Good luck and keep us posted.

John

[ledhedsymbols]

The single 12AX7 is a dual triode. It acts as a first stage audio amp and a phase inverter for the PP 6V6s. If I need more gain, I can always add another preamp stage after I test it.

[Shuie]

Octal preamps are cool. Do you have a decent 6SN7 or 6SJ7 in your parts stash? You could actually do something like an Alamo Amp2 with the 3 octal sockets on that chassis (6SJ7, single 6V6 & 5Y3) pretty easily.

[ledhedsymbols]

I ordered the parts that I'll need to rework the chassis, install an on/off switch, build a decent tone stack, add volume control and a new Jensen speaker. This will be my project over Christmas break. I'll figure out the circuit before then, and plan to have at least a working amplifier before the new year. Haven't decided what I am going to do about a cabinet just yet, the chassis I have isn't pretty. Cabinet will come later though... First thing's first.

Here is the existing schematic.

What it doesn't show is the external tone control and remote power switch/turntable power. Those were handled through a cable that plugs into the side of the chassis. A little bit of circuit tracing will show where that lives. I intend to build a Baxandall passive tone stack and start playing with values to fine tune the sound once I get it up and running.
Passive Baxandall


I'm going to stick with the existing PP 6V6 circuit for now. I don't see any reason to gut it and start over yet. Once I get this going, maybe I'll build a single ended amp like the Alamo you mention Shuie or a Fender Champ for a different sound.

[IROC]

Somewhat related to this thread, my cousin builds tube amps and mounts them in old vintage radios that my Dad refurbishes. He sells them on eBay. Pretty cool.

[stuartj]

Before any one starts building amplifiers - or tazers- at home, please view this important safety video. For the lols.


https://www.facebook.com/867371926689177/videos/921172871309082/

[DoninDEN]

I've been very happy with my VHT Pittbulls. You have to make sure they are a Steve Fryette version. Fryette sold VHT to a Chinese company a few years ago and now makes his amps under his name, Fryette. I have no experience with the newer Chinese VHT's, but the rumor is they are not as good. But they are very versatile amps with great tonal qualities at low or surprisingly loud volumes.

Here is a review of the VHT Pittbull 45 (Fryette VHT): https://www.ultimate-guitar.com/reviews/guitar_amplifiers/vht/pitbull_45?no_takeover

If you know about Fuchs amps and what the Dumble amps were, I have one of Fuch's original dozen prototypes he used to arrange his angel funding to get started. It's the closest thing, I believe, that you can get to a true Dumble, but with a lot more tonal range. It has a tonal discord that is is unnerving. The only time I felt like the way I feel when I play through it was the first time I saw Van Halen in the late 70's. The tonal discordance literally gave me a body shake for days. The subsequent Fuch's brand amps were much more refined, but this thing is a monster. I'd consider selling it for $5,000.

It is the prototype for his Overdrive Supreme (Dumble were called Overdrive Specials). Here is the current website: http://www.fuchsaudiotechnology.com/amps/overdrive-supreme

[DoninDEN]

For those who might be curious:

Here is a video with Fuchs explaining the background of his Overdrive Supreme off of the Dumble and demonstrating how amazingly subtle changes in the settings create huge tonal variation in the amp. In the first part he discusses how he started modeling his amps after Dumbles and around 9 minutes in he starts showing how responsive the tone, drive and reverb adjustments are.

http://youtu.be/iOEvd3T7Mjg

Here is an article on the Dumble that mentions George Gruhn selling one to Eric Clapton for $70,000:

The Find: 1991 Dumble Overdrive Special « Guitar Aficionado

Enjoy!

[ledhedsymbols]

I finished doing the conversion this weekend. I recapped it, replaced a few things that were out of tolerance, added a fuse, an on/off switch, and a pilot lamp. Hooked it up to the speaker...

It sounded pretty decent. I found it a bit "spanky" if that makes sense in the mids/treble range. I then built a tone stack like this:




It lets me tweak the tone so that I like it, but the loss of input signal is killing me! It can't really drive the speaker well, and it's much quieter than it should be.

As you can see from the schematic I posted previously, it only has one 12ax7 which is preamp, and phase inverter. I'm thinking it needs more gain to drive the 6V6s. I did the math, and adding another preamp tube would have the PT running on the ragged edge of saturation, and I don't want to risk my 60 year old transformer.

The current solution I'm working on is this: https://www.modkitsdiy.com/pedal/persuader_deluxe

Does anyone else have any good suggestions or ideas that aren't ridiculously expensive? I'm looking to get a clean bump in gain, and I'd also like to be able to drive the tubes into distortion which I can't do currently. The pedal would do both I think, but I'm open to other ideas to try.

[jmp81sc]

If I were you I would add a second 12ax7 for the Phase inverter and wire up the tone stack like the Fender 5E3 Tweed Deluxe. The 5E3 uses the second half of the V1 12ax7 as a gain stage to make up for the signal loss from the tone stack. The cool thing about the Tweed Deluxe is that it has two input channels that are very interactive so even though it only has a basic tone knob it has a wide variety of sounds available.

The other thing you could do is turn it into a single ended Tweed Princeton 5F2A, not many components, has a tone knob, and really sounds good with a 10 or 12 inch speaker.

[ledhedsymbols]

Originally Posted by jmp81sc

If I were you I would add a second 12ax7 for the Phase inverter and wire up the tone stack like the Fender 5E3 Tweed Deluxe. The 5E3 uses the second half of the V1 12ax7 as a gain stage to make up for the signal loss from the tone stack. The cool thing about the Tweed Deluxe is that it has two input channels that are very interactive so even though it only has a basic tone knob it has a wide variety of sounds available.

The other thing you could do is turn it into a single ended Tweed Princeton 5F2A, not many components, has a tone knob, and really sounds good with a 10 or 12 inch speaker.

Unfortunately, adding another tube would necessitate a new power transformer... I'm still going to try the pre-amp pedal, but I'm also looking at the circuits you suggest. I'll probably have to mock some of them up and then experiment a little.

I already drilled the chassis for the pots, but didn't add a volume control yet. I think I shall try the single knob tone control options, and then use the other hole for a volume control.

[WolfeMacleod]

Originally Posted by ledhedsymbols

Tons of interesting conversation and good thoughts from people... I expected no less.

I've looked at quite a few kits the last few days, and I've listened to videos of all the various models we discussed. I like the idea of the Supro, and I found a good kit for that one. I would need to figure out a cabinet, I do a good job with refinishing but carpentry isn't a skill I possess. I could build it as a head unity rather than as a combo though..........

Also, despite being one of the more expensive 5E3 kits I like the idea of the different circuits available in this one. Thoughts?

Tweed Royal 1x12 Combo – Build Your Own Clone

I have a kit from BOYC. I think it's the Champ kit. Bought it with the intent on building it. I'll trade you something for it... you're an electronics tech, you say?
I also know a guy who build cabinets that I can set you up with. He's local.