Guild Thunder 1 Project

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So these amps aren’t coveted like the old Fenders but my tech (who is one of the best out there, was Billy Gibbons amp tech for years, as well as had his own amp company) decided to revamp my 2 1965 Guild Thunder 1’s. I bought these amps more or less because of how rare they are as well as the cool unique sound and the unique choice of tubes Guild decided to make these amps with. The circuit itself is just wacky and needless to say Guild did many things wrong here with the circuit. My tech said it seemed like they were in the middle of testing and blueprints and just decided to rush into manufacturing these amps regardless of the design flaws. He had the two amps on the bench for atleast a month tweaking the circuit. The Tone stack was awful and the drift in cap values over the years was like day and night between the two amps. The bias cap values in the amps were the biggest issue, they are really high in these amps in general and the amps run really hot. And it produces this weird awful clipping at the end of a note regardless of how how the amp was pushed. So he decided to more less take Princeton Reverb specs and applied that to the whole tone stack. He did a few minor things outside of the tone stack as well as swapping out the old beat up stock CTS speakers for 30 watt Alnico Weber’s.

Yesterday, he calls me up and says their done. So i head over. We fire them up together in stereo while the amps are still on the bench….and wow, the tone that came out of those amps were incredible. I couldn’t believe how good he got these amps to sound. Definitely had a Silvertone/Magnatone/cranked tweed sound going on that was soooooo good. It didn’t take much to transform these amps into absolute tone monsters. And I feel like these amps are a hidden gem in the vintage amp world for sure. Granted stock they need some work to sound like this but just shocked how easy it was to totally transform these amps and make them sing with the best of any vintage/boutique amp. If you’re into vintage tweed pushed Neil Young tones, don’t pass these amps up. Take it to a tech that knows what he’s doing technically and creatively and tweak the tone stack (Princeton Reverb specs are what my tech roughly went by as the cap and power values are interchangeable ). A little tweaking went a LONG way here with this amp. I’ll definitely now be using this dual stereo set up for some sessions as well as gigs…..And I also own multiple vintage Blackface Twin Reverb’s as well as a few Badcat amps so that’s saying something lol.
 

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GGJaguar

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Welcome to LTG! Glad your tech got the T-1s where you wanted them. I kind of like Thunder 1's for what they are (bright, clean) so I've always left them stock.
 
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Welcome to LTG! Glad your tech got the T-1s where you wanted them. I kind of like Thunder 1's for what they are (bright, clean) so I've always left them stock.
Thank you! Appreciate it, yeah Im absolutely loving how these amps turned out. I was trying to upload a video for everyone to check out, but seems like I can only upload pics on this forum.
 

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Cathode bias caps are easy to change. What you have to understand is all Guild amps are multipurpose amps. Almost all of them were advertised as being suitable for keyboards or bass, so that may be why your tech didn't get it.
 
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Yeah advertised as such but really only suitable for anything with low impedance signals….. And it’s not that my tech had any issues with any of the components, that was never an issue at all. He’s got a masters in engineering and understands amps more than any tech I have ever worked with, so I think you may have misread my post. He had a lot of fun tweaking and experimenting with improving this circuit and took his time. Based on what he said and after opening the chassis up and everything I’ve read, the circuit is definitely unique and interesting to say the least. The pentode 6GW8 power tubes used were also pretty unorthodox for guitar amps at the time as they were primarily used in old table top radios and record players.

It doesn’t take much to take these amps to the next level. With a little ingenuity and understanding of amps and sound, these amps are gold. Wish I was able to upload videos here for ya. Unfortunately pics can only be uploaded on this forum.
 
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fronobulax

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It doesn’t take much to take these amps to the next level. With a little ingenuity and understanding of amps and sound, these amps are gold. Wish I was able to upload videos here for ya. Unfortunately pics can only be uploaded on this forum.

Welcome.

Since this clearly bothers you, enough to mention it twice, you are correct. Videos and sound clips need to be hosted at another site and linked to here. There are various suggestions for free hosts but they will almost certainly require you to make an account at their site.

Given the struggles it took to get LTG to host images, I'm not sure when, or even if, videos and sound will be upload options. But if you know of a site that uses XenForo software and allows such hosting, let us know. It might be easier than we think.
 
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Welcome.

Since this clearly bothers you, enough to mention it twice, you are correct. Videos and sound clips need to be hosted at another site and linked to here. There are various suggestions for free hosts but they will almost certainly require you to make an account at their site.

Given the struggles it took to get LTG to host images, I'm not sure when, or even if, videos and sound will be upload options. But if you know of a site that uses XenForo software and allows such hosting, let us know. It might be easier than we think.
Appreciate the warm welcome to the forum. And No worries, that’s a lot of work just to upload a little rough iPhone clip. Maybe eventually I’ll upload a link with a session or gig. And yeah I’d rather let the video and sound of the amps speak for themselves instead of me ranting about how good these amps sound lol.
 

shihan

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Welcome and congratulations on the T-1’s! A Thunder is on my amp bucket list, and your experience validates my desires. A stereo set up would be choice. Enjoy!
 

matsickma

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I also am a T1 fan! Speaker replacment is a must for me but I do keep one stock. I've had many over the years and had a T1 RTV as my first amp back in '66. I currently own a '65 black T1 RTV and a '67 beige T1 RTV. The '65 has a JBL D-120. Certainty the JBL wasn't added for power handling but I wanted the low end and clairty of the JBL and no speaker distortion.
Love the speaker driven reverb of the RTV and the psudo stereo effect from the seperate reverb speaker.
T1's are great little amps!
M
 

Nuuska

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Tonestack rebuilt to Fender Princeton type . . . ?

Does this mean you have some custom built amps in vintage Guild enclosures ?


Oh - welcome to LTG 😍
 

JohnW63

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I always wonder, whether it's a guitar or an amp, if it would have cost less to get what you were shooting for in the first place or to change what you have now to get what you wanted.

There is a guy around town that has one of these:
6-front-three-quarter-WEB.jpg


And put a small block Ford 302 V8 under the hood.

Would it have been quicker and easier to simply get a used Mazda Miata with 200hp?


The idea of a Magnatone sound out of a small-ish amp is interesting.
 

Prince of Darkness

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I always wonder, whether it's a guitar or an amp, if it would have cost less to get what you were shooting for in the first place or to change what you have now to get what you wanted.

There is a guy around town that has one of these:
6-front-three-quarter-WEB.jpg


And put a small block Ford 302 V8 under the hood.

Would it have been quicker and easier to simply get a used Mazda Miata with 200hp?


The idea of a Magnatone sound out of a small-ish amp is interesting.
Amazed that he could get such a large engine in there! The original engine is a 948cc A Series 4 cylinder, that Ford is five times the size. Later versions and their badge engineered MG Midget equivalents got progressively larger versions of the A Series, up to 1275cc, with the last Midgets getting the Triumph 1493cc engine, much to the annoyance of some MG enthusiasts!
 

JohnW63

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He popped the "bonnet" and gave me a look. The firewall was cut to allow the bigger gearbox and the engine did fit between the shocks, but the plugwires had to turn 90 degrees very quickly.
 

lungimsam

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Gibbons used Trainwreck amp heads in the late 1980’s iirc
 
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Welcome and congratulations on the T-1’s! A Thunder is on my amp bucket list, and your experience validates my desires. A stereo set up would be choice. Enjoy!
Honestly I can’t go back to a single amp setup now after playing in stereo or with a 3 amp setup for some time. EQ’d correctly there’s a fullness and harmonic richness that just cannot be achieved with a single amp setup. And I feel like a proper stereo or multi amp setup is the key to getting a huge rich sound with low wattage amps. Neil Young had it right with his live rig of cranked tweeds!
 
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Tonestack rebuilt to Fender Princeton type . . . ?

Does this mean you have some custom built amps in vintage Guild enclosures ?


Oh - welcome to LTG 😍
Hello and thank you! I wouldn’t say it’s a full on custom amp in a Guild chassis, but some key components were tweaked for sure. The tone stack is tweaked to make the amp run and sound smoother. And since values in Thunder 1’s and Princeton Reverb’s share similar values thats what the changes were based on. Also, the alnico Weber 12A125S speakers were a huge contributer in also transforming this amp.
 
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