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Originally posted by Richard Guy

Nice Pics Phil! Great detail. What camera are you using?

Rosin Core solder 60/40 or 63/37 is very good to use. Since Phil was using silver solder, the flux was helpful. Flux is not recommended for novice builders as the flux, if used too heavily, can melt/run into the base areas of the tube sockets and cause issues. This is true with any electronic project. Phil has been soldering since the Chicago Fire. Don't worry Phil, we won't tell who started it ;^)


Oops, my "secret" is out. :o;):D


Good point about the flux Rich. I actually only needed to use it in a few spots, and you're right - if you use standard rosin core solder, you won't really need to use flux.

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Originally posted by Phil O'Keefe

In this review, we're going to be taking a close look at a couple of Gary Gerhart designed tube guitar amp "DIY" kits from Guytronix - the 8 Watt EL84 based Ardmore ($299, direct from
), and the $249 1/2 watt (2 watt optional) Gilmore Jr.

First off, a couple of disclaimers. Normally, a reviewer obtains a "loaner" of the product to be reviewed, and return or purchase it at the end of the review process. In this case, we're dealing with a pair of tube amp kits, and as such, they can't really be assembled and reviewed and then returned in the same state as they arrived in.
And since putting together a tube amp takes a certain amount of time and labour (stay tuned to this thread for an idea of exactly how little or much
), and since that itself has value (IOW, the company can take the returned / completed amp and sell it for more than the price of an unbuilt kit), Rich at Guytronix and I negotated a deal where I would built both kits, do the review with complete freedom, and send back only one of the completed amps. That way, he doesn't profit from my build time, and I "pay" for whichever amp I decide to keep by the labor I put into building the amp I return. So right upfront, you know I'm keeping one of these two kits... and since these are Pro Reviews, you're all invited to participate and help keep things honest and above board.

There are many potential uses for a small, low power, yet toneful tube amp. Practice at home and recording purposes are two places where such amps are commonly used. In this review, I hope to cover the actual kits themselves, the build process and the difficulty level and experience / skills you'll need if you decide to build one, and what level of customer service and assistance you can expect to recieve from Guytronix. Additionally, we're going to fire up the studio and do some tracking of the completed amps so that everyone can get an idea of how these amps sound, with particular attention to how well they perform in a studio recording environment - after all, this IS a studio forum.
But we'll also break out the SPL meter and see just how loud a 1/2 or 8 watt head really gets. That should be of interest to those who are considering one of these amps to use for practice.

What I'd like from you is your participation. Let me know if you have any questions. If something's not clear, point it out. If you have built one of these amps, feel free to voice your opinions about them and tell us about your experiences. Rich from Guytronix will also be participating and will be making comments and answering questions as appropriate as well. He's a good guy, and you'll find him easygoing, knowledgeable and helpful.
I'll also be asking for suggestions regarding what you want to hear insofar as clips, and we might even try to set up an in-studio session (at my place) with a few of you to let you get some hands-on, in person playing and listening time with the completed amps. We can track some clips of your playing, and give you an opportunity to tell everyone what you think based off firsthand experience playing through the completed amps. If you're interested in participating in that part of the review, please let us know.



Any clips on the Ardmore? I've heard the Cilmore and it was OK, not really my thing, but still cool.

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Any clips on the Ardmore? I've heard the Gilmore and it was OK, not really my thing, but still cool.


We'll be getting to that - please stay tuned. :)


And as I mentioned before, we'll see if we can't get some of you to come by the studio and supply the hot licks while I take care of the recording part. ;)

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Originally posted by Ancient Mariner

Looks interesting, in a Christmas-afternoon-build kind of way. A nice simple kit to get someone started. Look forward to hearing it too.


Yup, if you're an experienced builder, you could probably knock one out in an afternoon. IMO, they're definitely a kit that would be suitable as a "first amp project" type build. As far as tone and features of the amps, we'll be getting to that. Stay tuned. :)

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Since I've gotten a few PM's asking about the Cold Heat soldering tool, I'll make a couple of quick comments before we move on.


The Cold Heat tool uses a carbon based "split" tip. It's actually somewhat fragile and can be easily broken if you apply too much pressure or force to it, although I have not managed to break a tip yet. The Cold Heat soldering iron comes in two versions - a standard model and a "pro" model. I bought one of each to test. A "standard" model from my local Radio Shack, which I purchased while waiting for the "backordered" pro unit that I purchased online to arrive. The pro model is definitely the one to get, since it has more power and a high and low power setting. The optional magnifying glass attachment is pretty much worthless - I thought it would be nice to have - especially since my eyesight at very close distances and for fine detail has really deteroriated over the past couple of years (middle age sux in some respects), but attaching it - and keeping it attached to the iron is tricky, and getting it angled right so that it's not in the way of what you're working on, doesn't block the iron's built in light, and still allows you a magnified view of what you're working on is an excersize in frustration.


The tip of the Cold Heat iron doesn't get hot until the two halves of the split tip make contact to the same piece of metal, thus completing an electrical circuit and causing the tip (and hopefully the work) to heat up. A red LED lights up when the tip is making proper contact. The biggest problem I had was getting both halves of the tip to touch the same thing at the same time. Even when I could see (using an external magnifying glass attached to a boom) that it was making proper contact, the LED didn't always light up and the work didn't heat up. Once it does, the iron - even the "pro" model - really lacks the power to properly heat the work unless you hold VERY still (keeping that connection "just so") for a while while the work heats properly, and in my experience, it takes considerably longer than doing the job with a good traditional soldering iron.


After trying this tool for a while, on a couple of different types of things (not just these amp kits), I would tire of the fiddling and just break out the Weller. It does work as advertised in the sense that it does cool down very quickly - unless you still happen to have a small blob of solder stuck between the two halves of the tip, in which case it might remain hot... so in that respect, it does what it says it does. But it really lacks the speed and power of a good traditional iron, and I personally can't recommend it for much beyond a quick cable or switch repair. Having it around for that can be useful though.

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To add to Phils above soldering iron message; please do not use soldering 'guns' for any electronic soldering that especially has solid state (transistors, FETs, MOSFETs, diodes, integrated circuit chips, etc) components as the soldering 'gun' types inject current into the work while operating and can damage the circuit. I like using a Weller soldering station with an adjustable heat range to 850 F. For a stand-alone soldering iron, I recomment a wattage of no less than 30 watts. I tend to like 35 watters and above.

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Got my Gilmore Jr. kit back in August. Got nothing but good things to say about it and about Richard Guy's customer service. The kit was easy to build, thanks to the clear instructions and quality components, but I still had a few questions...and Rich was very prompt and thorough in answering them.


I've since added the V mod and the 2-watt mod; both serve my needs to a T.


Rich also helped me acquire a pair of Weber speakers for this amp; unfortunately, I haven't been able to afford the materials to build the cabinets yet. Been running it through a 2x12 cab and it sounds GOOD. I expect great results when I get the 2x8, 16 ohm cab put together.


I rate this: :thu:

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Sorry for the delay, let's continue. :)


If you look at the last photo I posted, you can see that the components have been soldered to the turret board. That's your next step. It's really not difficult, but there are a couple of things to keep in mind:


First of all, when applying more than one component that attaches to the same turret point, it's usually best to solder all of them at once. Just wrap all of the components 1/2 way around the turret post, and then solder them all at once. Then use the side cutters to remove any excess length of wire from the components, as close to the turret as you can get. You'll probably find it easiest to install everything if you start at one side of the turret board and work your way across the board to the opposite side.


Another thing to be careful of is getting the orientation of any polarized parts correct. Again, all of the polarized parts, such as the black with blue striped capacitors and the diodes (the components at the far right side of the board in the picture above) are seperately bagged in the kit, and clearly marked on the components and in the instructions to help you know which way to install them. For electronics vets, this is simple stuff, but if you've never built anything like this before, you'll appreciate the extra thought that went into seperating these parts in an effort to make things easier for you. :) Getting the orientation of polarized parts is crucial - install these parts backwards / "reversed" and your amp isn't going to function properly.


This is a good spot in the review to make a little confession. If you're an old timer like me, then you might have problems with close distance vision. Yup, I confess - I use reading glasses these days... but even with them, I sometimes had difficulty reading resistor color codes. Your multimeter can come in handy there... just set it to measure resistance, and rather than having to struggle and squint to make sure you've got the colors (and thus the value) figured out correctly, stick the meter's probes on each wire end of the resistor, and you'll get the value displayed in big numbers on your meter. That's one reason I like digital multimeters. ;):D Just be aware that resistors have a tolerance range - IOW, the actual value of the resistor when measured with a meter may not be exactly what is called for in the instructions, but it should be within a certain range - +/-2% or whatever, depending on the tolerance. So if you use a meter to help you sort through the resistors and check their values, don't be concerned that they're not dead on exact to the schematic. A good work light and maybe a magnifying glass can also be helpful when trying to use tired old eyes to see fine details. ;) And when all else fails, give Rich a call. Again, I confess - I had to do this on two parts of one of the two kits (I just couldn't make out the markings) and Rich was more than helpful with it.


Make sure you double check your work as you go along. "Measure twice, cut once" is good advice for electronics as well as carpentry... ;) Just go slow and make sure you're using the right parts in the right place. If you're an inexperienced builder, once you have everything mounted to the turret board and have double checked everything, it's a good time to take a break.

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Originally posted by FWAxeIbanez

anybody care to elaborate on why the Cold Heat tool just isn't suited well? would the newer Cold Heat Plus do the trick a little better? as you can tell I haven't soldered much...


I wrote a few general comments and opinions about the Cold Heat soldering tools - you can find them near the bottom of page two (second post from the bottom) of this thread. :)

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