Garnet GS100 amp - Chassis removal help? SOLVED

[Lectroid]

A guy wants me to look at his Garnet GS100.  I can find a G100 schematic, but it's not an exact match to what I see in the amp.  I paged around Garnet's current website but I didn't find anything about it.  On the label it says it's a  "GS100tRW".   No idea what the "tRW" means. 

Anyone know of this amp?  It has a pair of 6L6s with reverb and tremolo, looks like it would be something roughly equal to the Fender Pro Reverb.

Is Garnet known for fiddling with specs during the production run.  Tweaking amps to try out a new idea?

I've been to Garnet.com.  Any other sites about Garnet amps?

Thanks!

[tubenit]

Garnet Schematics - Tube amp Schematics (el34world.com)

[Latole]

Garnet Schematics - Tube amp Schematics (el34world.com)

There is no GS100.

[Lectroid]

Thanks, tubenit,

Yes, I found a "GS100R" schematic there that is pretty close.  I've been using it so far, and it only has minor differences between this GS100tRW and that schematic.  It'll be enough of a guide.  I was surprised that Garnet amps are a little rare, but not really sought-after.  This one seems to be a quality product, well-built. 

[Latole]

You are right Garnet are great amps, I have one at home, a combo.

[Lectroid]

And here I am hijacking my own thread on a different issue.   

I can't seem to get the Garnet's chassis out of its cab, after 2 hours this morning trying to remove it.   It looks like a std Fender chassis setup at first.  Remove the chassis mounting screws, and then slide the chassis out the back.  Easy, right?

It would be, except the power transformer is mounted too far out on the end of the chassis.  I removed the six counting screws, no problem, and the chassis falls free.  But when I try to slide the chassis straight out the front or out the rear opening, the outer edge of the PT laminations hits the vertical side piece that the upper back cover screws into.  Here are shots of the PT from the rear, and from the front.  (You'll see I removed the speaker baffle to get more room but it didn't help the PT problem.)  The vertical side pieces show no sign that they are removable to get the chassis out.

The chassis fits very snugly from side to side in the cab.  There is no wiggle room on either side that would allow me to drop just one end of the amp to free up space, and so slide it out through the front or back openings.  Just trying to get it into position for screwing down is tricky because it binds so easily with any movement.   

I'm stumped. The chassis is the proverbial ship-in-a-bottle.  It appears to be impossible to get it out for service, but I don't believe that for a second.  So obviously I'm missing or overlooking something.  But what? 

Any ideas how to get this Garnet chassis out?






 

[Latole]

  "  Any ideas how to get this Garnet chassis out?  "

-  Pull and push. What else?
 But it will have to be done perfectly straight, not pulling or pushing one side more than the other. Incredible how badly this cabinet is made .

Good luck.

[Latole]

Insert a slightly longer piece of wood to “open” the sides a little more.
In front and rear of the cab.

In other words, widen the cabinet. It probably doesn't take much

[Lectroid]

I don't think pushing out the cab will help.  If you check the pics again, you might see that the PT needs about 5/16" clearance that isn't there.  The PT is mounted so far out, so near to the inner side of the cab, that the laminations are physically tucked in behind the vertical door cleat.  The amp slides out so far, then the side of the PT hits the back side of the left-hand clear.  Jiggling them won't work like it would with a Fender.  The cleat is actually preventing the chassis from being moved out the rear (or the front) openings.

It sounds crazy, I don't believe it was built this way, but that's what I see.

[Platefire]

Makes me wonder if they didn't copy Mesa Boogie as on my Rocket 440. As I remember it has a grounding connection in the top of chassis(to upper shielding?) and until you backed that screw out a bit, the chassis wouldn't slide out but it did tell you that in the manual. Have you got a manual?

[Latole]

I don't think pushing out the cab will help.  If you check the pics again, you might see that the PT needs about 5/16" clearance that isn't there.  The PT is mounted so far out, so near to the inner side of the cab, that the laminations are physically tucked in behind the vertical door cleat.  The amp slides out so far, then the side of the PT hits the back side of the left-hand clear.  Jiggling them won't work like it would with a Fender.  The cleat is actually preventing the chassis from being moved out the rear (or the front) openings.

It sounds crazy, I don't believe it was built this way, but that's what I see.

I'm sorry, I can't see with pictures

[Latole]

Garnet didn't build the cab around the chassis. The chassis had to be slid into place. So it has to come out the same way.
How do I go about it? That's the question.

Patience and reflection are required

Platefire,
I never see a vintage amp manual show you how to pull out a chassis from a cab.

[Willabe]

I never see a vintage amp manual show you how to pull out a chassis from a cab.

It would if there was a trick to getting it out.

[Latole]

I never see a vintage amp manual show you how to pull out a chassis from a cab.

It would if there was a trick to getting it out.

There are always a trick, some are easy some are not.
These kind of job are for qualified tech. Amps builder think a qualified tech will know how to.

I did not say for this amp there are not building error from Garnet.
Has the cabinet wood dried out over time and shrunk?

[Willabe]

I never see a vintage amp manual show you how to pull out a chassis from a cab.

It would if there was a trick to getting it out.

There are always a trick, some are easy some are not.
These kind of job are for qualified tech. Amps builder think a qualified tech will know how to.

I did not say for this amp there are not building error from Garnet.
Has the cabinet wood dried out over time and shrunk?

Your dancing around what I said.

There's not always a trick, most times you don't need any trick to get the chassis out.

And there's no way the cab shrunk that much to not allow the chassis to be removed.

[Willabe]

Try this, it might work;

See if you can tip the chassis vertical and then push 1 end of the chassis to a front corner, then swing the other end out to the back corner. Chassis is now lined up with the cab diagonally. The cab's diagonal is longer then the chassis. Should have room now to swing the chassis out.

Might be only 1 combination of this will work, knobs up/knobs down, preamp to the front/PT to the front, 4 different chassis position combinations.

Like this;

Tip the chassis vertical, knobs down, with the chassis still vertical, swing the chassis preamp end all the way, tight, into the front inside cab corner. Then swing the chassis PT end out towards the back.

It might have just enough room to swing it out this way.   

[Latole]

Your dancing around what I said.

I'm sorry, I didn't want to offend you

There's not always a trick, most times you don't need any trick to get the chassis out.

I sometimes read a "beginner" ask on forums that you and I would do with both eyes closed. So for this member, yes there was a trick


And there's no way the cab shrunk that much to not allow the chassis to be removed.

Shrunk cab ? I don't know,
 What could have happened then?

[Willabe]

What could have happened then?

See reply #15.

If that works, then they built the cab that way for some reason.

He didn't post pictures showing what the wood cleats support.

[Latole]

Is there tolex wedged between the cabinet and the frame?

Yes; can you remove it, you may have more room to slide

[Latole]

What could have happened then?

See reply #15.

If that works, then they built the cab that way for some reason.

He didn't post pictures showing what the wood cleats support.

I read it and "liked " your answer #15
I do that way sometimes.

[Willabe]

Is there tolex wedged between the cabinet and the frame?

Yes; can you remove it, you may have more room to slide.

There's no tolex on the cleat.

He posted 2 pictures, there not very good. The picture of the PT side you can't see the back outside of the cab that's in the way. It's just white. 

Pics are in reply #5.

[Latole]

Is there tolex wedged between the cabinet and the frame?

Yes; can you remove it, you may have more room to slide.

There's no tolex on the cleat.

He posted 2 pictures, there not very good. The picture of the PT side you can't see the back outside of the cab that's in the way. It's just white. 

Pics are in reply #5.

You are right ,

Slide vertically as you say is worth to try.

[bmccowan]

I paged around Garnet's current website but I didn't find anything about it.  On the label it says it's a  "GS100tRW".

According to the Garnet registry http://www.garnetamps.com/registry.htm that model number is called a Jammer and was a combo with a 12" speaker. No listing for a head version.
So, do you think the cabinet is original? I suspect it is not. There are many photos of Garnet cabinets online and probably easy to determine if your cab is something Garnet would have built. Again, I suspect not. And if not, it is entirely possible that a misguided owner mounted the chassis and then finished the rear of the cabinet.
As discussed above I have also manipulated a chassis out of a too-tight cab - its kind of like those aggravating wrought iron puzzles
But is also sounds like you have tried your best at that. If so, I would try two things after getting an OK from the owner. Try to loosen the PT with the screws - sometimes if the nuts inside the chassis are well secured, the PT can be lowered. But I'm not optimistic.
Next attempt - carefully pull away any tolex and with a sharp backsaw, carefully cut and remove the wood cleat just below the level of the PT. After electronic work, rework the cabinet to how it should be built, and remount the chassis. This is likely where you will end up IMO.
BTW, as Willabe said, better photos would help.

[Latole]

Pictures of the cabinet may show if original or not.

A Jammer Picture on Reverb

https://reverb.com/ca/item/16549512-vintage-garnet-jammer-g250r-combo-amplifier

[Lectroid]

Everyone,

Thank you for all the eyes and brains on this.  You all have great suggestions.  I apologize for the pictures.   The cleat IS covered in Tolex, only my flash picture made them look white.   I'll try to get some better-lit shots.

So far, I have tried twisting the chassis 'sideways' in the cab, (yaw) and forward, rearward (roll), so as to try to lower it out that way.  Can't--there is not enough clearance on the sides to rotate it.  It is a very tight fit, side to side. 

I briefly thought of the handle screws, but they aren't the problem.  There were some isolated areas of Rolex binding.  Some of those I could glue down flat, and I trimmed a couple of places where they wouldn't show.

If I were reading this, I'd be sure that the poster was either incompetent, ignorant, or stoned.  (Pretty sure not the last one.)   I am sure there's a simple answer--this is clearly a production amp from a known maker.  It had to have been built to be easily serviced.

Thanks again all.  If there really was a 'secret', I'm sure you guys would know it.  Stand by.  I'll post better pics in case someone might see the thing I'm obviously missing. 

Also-- Yes, it is a real Garnet.  What I've gathered is that the Jammer and the Revolution II / III were similar to each other.  Anyway, cab is a real Garnet to my eye.  Nice white Tolex, well-made, the corner guards, the knobs and panel are typical for the late 70's period.  I'll post a picture.


 

[Willabe]

I'd ask Kevin O'Connor, London Power amps, he's in Canada and has worked on Garnet amps. He might have worked on that amp before.

He has a web site and an on line forum.

His company;

https://londonpower.com/

His forum;

https://theultimatetone.com/

[mresistor]

If the speaker baffle is removeable then maybe you take the baffle out and the chassis slides out the front. 

[Willabe]

If the speaker baffle is removeable then maybe you take the baffle out and the chassis slides out the front.

He said he tried that, but the baffle cleats are still in the way. 

Somethings not right here.

Garret didn't build a cab you can't get the chassis out of. How did Garret get the chassis in? 

[Lectroid]

I got it out.  I put the amp on its top.  From that angle I could see that, the front cleats being shorter than the back cleats, I just had to drop the front of the amp as I pulled it out the front.  In other words, when the amp is on its top, roll the chassis downward as you pull it toward you.  If the amp had been right-side up, you would lift the panel edge upward as you lift the chassis out.

As suspected, I was just missing the obvious.  Thanks for all who tried to help, ands sorry for wasting everyone's time.    Here's a better shot of how the PT fits behind the cleat.

Also a gut shot of the whole amp. I will do more if anyone is interested.  The little red and white bell wire going off is the reverb send/return lines.  They don't look shielded. 

The reverb driver is a single 12AU7 stage.  How does it put out a high enough current equivalent to the two 12AT7 stages in a Fender design? 

The reverb pan itself is 'folded' inside; it's just one single spring strung into an "N" shape inside the box.  It's produced  by "Folded Harmony" and made by "the beautiful girls of Missouri."  It's printed right on the unit.

[bmccowan]

 
I'm interested in how this goes.

[Lectroid]

I dug into the amp a little this afternoon and had some odd results, so I'm, starting a new thread on the troubleshooting process.   Thanks again for everyone's help.

 

[Latole]

Congratulations.

Now, am I missing something ?  I don't see anywhere where you describe the problem with this amp.

[Platefire]

Glad you got it out! 

Har! In defense of my statement about the Boogie. The manual don't tell you how to pull the chassis, it just has a note that the ground lug has to be backed off before pulling the chassis

[Lectroid]

Congratulations.

Now, am I missing something ?  I don't see anywhere where you describe the problem with this amp.

@Latole,

I opened the thread just to get some help to get the danged thing out of its box. Once I can troubleshoot it, I'll open another thread if I run into any problems with it. Thanks for the interest.   

[Latole]

I don't see how my request is unjustified. Is it so secret?

[Lectroid]

Not secret at all. The owner says it went silent and that’s all he knows. I refastened the bass cap that had come undone. Now I hear my test tone through the amp, but it’s at very low power for a pair of 6L6s. I’ll be starting a new thread on this amp soon.

[Latole]

Not secret at all. The owner says it went silent and that’s all he knows. I refastened the bass cap that had come undone. Now I hear my test tone through the amp, but it’s at very low power for a pair of 6L6s. I’ll be starting a new thread on this amp soon.

Thanks for your reply, it's much appreciated, I was curious.
As far as I'm concerned, don't feel obliged to start another topic.