Bolting to Amp Stands

[hitmanray]

I am eagerly awaiting the arrival of a MonAmour amps kit. I plan to purchase some amp stands from Monoprice to put the amps on as they will be on the floor directly behind my speakers. I want to bolt the amp base to the stand. I plan to purchase some standoffs to maintain the required ventilation gap between the bottom of the amp base and the stand.

So here's the question. Is it better to get a rigid standoff and simply bolt the base to the stand forming a solid mechanical connection, or should I source some anti-vibration standoffs or grommets or similar to provide some vibration damping between the base and stand?

Rigid standoffs will be much easier to source and use, and the amp stand itself is on spikes so has some isolation. I'm also not really sure how much impact vibration damping has on electrical components in terms of sonic performance, but given the investment I am making, I thought it wouldn't hurt to canvas some opinions.

Thanks in advance for any thoughts or opinions.

 

[Paul Birkeland]

What is the purpose in fastening the amplifier bases to the amp stand?

 

[hitmanray]

Excellent question Paul.

The primary reason is I have 3 fairly young kids. They are not allowed in the "music room" on their own, however, I'm in risk mitigation mode and bolting the amp to the stand creates another barrier to the chance of them getting at the underside of the amp and the associated risks.

A nice secondary benefit is that I will be able to "mount" the amps on the stands perfectly centrally, thus satisfying my minor OCD about things being lined up correctly.

I figure by bolting I would be able to get under the amp should I want to upgrade something at some point in the future.

I'm perfectly willing to concede I may be overthinking this, but figured it shouldn't do much harm to bolt the base and stand together.

 

[Paul Birkeland]

Well, the chassis plate could still just be lifted off the wood base. 

I suspect if you got eight 8-32 x 2" long standoffs and threaded them onto the screws that hold the power transformer onto the amp, you could then drill holes in the amp stand and bolt each amp down in that manner. 

 

[hitmanray]

Thanks Paul, that's a really good idea and much better solution. I had intended to just glue the chassis plate to the base.

But I think what you are suggesting will be better in terms of reducing the risk and also more discreet in appearance.

Thanks for the input. Will be sure to let you know how I get on.

 

[Paul Birkeland]

Thanks Paul, that's a really good idea and much better solution. I had intended to just glue the chassis plate to the base.

Long ago we used to recommend this, but it makes it a total pain to work on the amps later.

I should mention that you want female standoffs if possible.  You could just set the chassis plate on the amp stand where you want the amp to go, then drill 3/16" holes right through the holes in the plate where the transformer goes.  Be sure to use washers between the #8 screws and each side of the chassis to keep the standoffs from ripping into the stand too much.

 

[grufti]

There might be an alternate way to secure your amps with something like this. RECOM recommends it for mounting their power supplies. It's not as secure as an amp that's screwed down and I don't want to be responsible for hurting your kids. Future servicing would be easier.

https://www.mouser.com/ProductDetail/Wurth-Elektronik/709440800?qs=%2Fha2pyFadujcD97uA%2Fzd%252B89qrCSkwWQcdl78FUsS8vahcWVhTwFFOg%3D%3D

You had me baffled with your intent to bolt the amp to the stand, but it makes complete sense and I will consider it from now on.

 

[Doc B]

You might want to look at Barry mounts or Lord Plateform mounts. They would allow securing the chassis while also damping vibration.

 

[hitmanray]

I did some internet searching yesterday and have ordered some standoffs. 3/8" HEX 8-32 x 2". I have ordered 8x female-male and 10x female-female. Less than $20 total. I figure one F-M and one F-F linked together should give me the 4" I need and allow me to run a bolt up through the stand.

I did seem some insanely cheap standoffs on Grainger but the dimensions were a bit weird and I wasn't sure how to make them work (total length was double the standoff length, so 2" standoff was 4" long). $0.39 for 10 if someone wants to check them out.

I also like Paul's idea of drilling the pilots in the stand using the chassis plate before starting any building. That way I can make sure they are lined up perfectly centrally.

Doc, I like the idea of the Lord plateform mounts. However, I'll be honest, I think my skill level is probably not high enough to make a good job of getting them installed accurately enough.

I did think about getting some anti-vibe washers/grommets along with the metal washers Paul suggested previously to create some isolation between the amp and base. I think I will just have to get a few things and experiment when the time comes. Can't get my head around all the stack up tolerances to work out what size of washers I will need. Get a variety and keep experimenting until it's secure seems the best bet at this stage.

Thanks for the link Grufti. I think at this stage I'm sold on the standoff suggestion from Paul. I can picture how to make that happen in my head, but I can see how what you have suggested would be a nice clean solution.

Thanks for all the suggestions and links.

 

[hitmanray]

After a bit of trial and error I have finally managed to get my amps bolted to the amp stands so thought I would circle back around to share my learning and results.

Took a few attempts at getting the right standoff length but what I ended up with (slightly ugly but functional) is a 2" F-F, 1/2" M-F and 3/4" M/F to give me a 3-1/4" F-F standoff. The gave me somewhere between an 1/8" and 1/4" clearance between the standoffs and the amp stand once installed on the PT-10 bolts.

I used 1" 8-32 pan heads to go up through the amp stand into the standoffs.

The first standoffs I bought were 3/8" HEX. I found 1/4" HEX much better when connecting to the PT-10 bolts as it all gets a bit tight around there with the terminal strips and a few cables running nearby.

The result is great. I'm not sure I would pick up the whole assembly by the wood base of the amp and rely on this arrangement to carry the weight of amp stand, but that shouldn't ever be really necessary.

Thanks everyone for the input and if anyone has any other questions please let me know.

 

[Paul Birkeland]

That turned out great.

 

[Karl5150]

I use the same stand for my HT receiver, reasonably sturdy and reasonably priced.
I see the bases match the walls, nice touch and quite unique. How was the prep?
Karl

 

[EricS]

That looks GREAT!  I like the color matches and that the amp is tucked away behind the speaker.  This is likely to help keep it out of harm's reach.  Nice implementation!

 

[hitmanray]

Sorry for the delay in following up, been a hectic week adjusting to the new way of life.

Thanks for all the positive feedback. I'm really pleased with the overall result, and it really wasn't too bad to achieve. Best advice was using the chassis plate to mark the holes before starting the build, that helped no end and I was able to get the amp lined up right in the middle of the stand, which is really nice for my mild OCD on the back end.

Honestly the wood finishing was the thing I was most worried about. My previous build (Crack Amp) I didn't do anything with the wood base as I was too eager to start building and never got back to it. I did have all sorts of ambitious ideas from powder coating the chassis plate to getting a high gloss mirror finish on a red tinted wood stain, but in the end decided to go simple. There was no special prep beside ensuring the wood surface was clean. 3 light costs of standard household paint (left over from when the room was painted about 4 years ago in truth) using a smooth finish foam roller deems the results as seen.

It's a bit "eggshelly" up close (which I think can be seen in one of the pics). Ideally I would get some higher quality paint and spent the time sanding an refinishing to get a really smooth coat. And I did think I should get some matte lacquer to protect the paint over the long term, but for now everything is bolted down and I am enjoying the amps for what they were designed for.