Looking for a fanless, small, cheap class D mono power amp

[Spectre Gunner]

Is cutting a hole for ventilation somewhere on the box an option?

 

[Paul Szegedin]

Thanks for all the great suggestions. I have been using this thing for noodling at home (in a case with the preamp) and it's fine and sounds good, but bulky. I was thinking a modern class D amp would be cheap, more powerful, and small -- but I'm starting to think @Giraffe is right. The prices are not exactly tempting. I've saved thousands DIYing various things, so I'm a real cheapskate. I will probably just keep my eyes peeled for a cheap, smaller donor than what I have. The world is flooded with used rackmount power amps - I don't want to spend $400 for 200 watts.

For guitar I love great tube amps, but for bass, I kind of like the tight, deeply scooped sound of my GK -- a lot of bass amps sound too soft and midrangey to me -- but I also just have a sentimental attachment to it.

Crown XLS1000 - not mono, but weighs about 9 lbs. I recently started using one with a BBE BMAX-T preamp - loving it so far !

That sounds good - I used to have one of those great BBE preamps and stupidly let it go.

Sometimes the heatsink could be bigger than a fan. Why don't you want a fan?

The noise -- using at low volume in a quiet place and only need low power. I find that heatsinks are fine for low power ss amps -- never had one overheat.

Have you checked out the TC Electronics offerings? I keep one of their 200w amps as a backup: very small, light, inexpensive.

This thing looks great - a lot like the Trace Elliot Elf that kicked off this line of thinking. I love the idea of slipping a bass head in my pocket.

 

[Passinwind]

Thanks, I'm definitely a DIY'er, and this is for home use and small scale stuff, so those ICE units are a good lead for me. But I don't know if I'd agree they're crazy cheap.


This is exactly what I did up to now with this amp, but the power amp is a little bit too underpowered and big (class A, huge transformer) - it's an older one.

I saw one of the Trace Elliot amps at a guitar shop and said, yeah, I need to put together one that small, for less money.

If you mean the Elf, that's not very likely at all to happen IMO and IME. Fanless? Not a chance. Enclosures are the classic deal breaker for DIY builds if you want something gig worthy, price some and I think you'll see what I mean.

And lots of people are recommending "illegal" solutions fior US residents here (ie. e. not FCC approved), but that's certainly nothing new. There's an exemption for experimental builds though, please do your homework on that.

From my perspective, I've built four fanless Class D bass amps for personal use and don't own any commercial pieces at this point. The economics made using the 700 watt ICE module most attractive in my case, but I was depending on the largesse of people a bit higher up in the food chain in the industry.

 

[sears]

If fanless was the main thing, and you were willing to make some compromises, a used Crown K1/K2 would be my choice.

 

[yodedude2]

do post whatever you come up with, i think many of us folks would be interested. EDIT: NEVERMIND


the newest pithy comment:

fanless, small, cheap -- pick any 2

 

[Abe-of-Bass]

Make sure you check out the Quilter Interbass. It may be rated for lower wattage, although I bet you'd get a lot more out of those watts than you might think. It's perfectly flat with the EQ set at noon, although you will get a bit of drive if you crank the gain. Perfect for your situation, as long as it can produce enough volume for your needs, and cheap enough to give it it a try.

 

[BassNugget]

Oops, that has a fan, sorry.

300 also has a fan.

 

[Slevage]

FYI: I used to use an Acoustic Image?
2 channel, 1000w at 2 ohm version.

Got rid of it because I didn’t like the sterile sound for BG, but sounded great for EUB/DB.

It shut down twice at an outdoor gig, running at 8 ohms on a 90 degree summer gig under a large tent.
Luckily, the person throwing the party was able to give me a fan to keep the amp running for the rest of the gig.

 

[BassNugget]

Crown XLS1000 - not mono, but weighs about 9 lbs. I recently started using one with a BBE BMAX-T preamp - loving it so far !

I use a Crown XLS 1002. It has a fan, but I have not been able to get it to come on while running 8 ohm loads. Dead quiet amp.

I also think the Harley Benton Bass Block 300 B may not need its fan running 8 ohm loads. I have used those ice modules before with no fan in a chassis about the same size (for 8 ohm home audio). I think for under 8 ohms the fan would be necessary. @agedhorse has a lot of experience with these modules, so maybe he can add some value here.

 

[agedhorse]

DIY because you are a cheapskate often ends up more expensive than other options. Also, in the quest for cheap, you will often overlook much better values that might be slightly more expensive.

There are used amps available for less than $200-$400, but for everything you have to factor in shipping.

 

[DJ Bebop]

DIY because you are a cheapskate often ends up more expensive than other options.

Then there's the unintended expense of head and heartache

 

[Paul Szegedin]

DIY because you are a cheapskate often ends up more expensive than other options.

It really does not.

@agedhorse I would appreciate if you would add me to your "ignored" list so that you won't see my posts and respond to them. You and I don't see eye to eye.

 

[Bass Jones]

There are a number of small class D heads that have very quiet fans. I have Markbass Nano 300 and I don't even notice when the fan comes on. I had a TC BH550 that also had a fairly quiet fan. Compared to the TH500 which sounds like a wind tunnel when the fans kicks in (but it's still my favorite cause it just sounds good!)

I think it has to do with the fact that the TH500 case is very thin aluminum and it resonates loudly when the fan is on. The Markbass and TC cases use pretty heavy aluminum. Just my guess.

I'm always tempted to DIY to save money but it often ends up being a false economy. All 3 of the above class D heads I bought for under $425 with the Nano just under $300.

 

[agedhorse]

It really does not.

@agedhorse I would appreciate if you would add me to your "ignored" list so that you won't see my posts and respond to them. You and I don't see eye to eye.

You have an odd way of expressing gratitude towards those offering help. YOU asked the question, others offered answers (including the same answer I offered).

When I asked you to PM me, I was going to GIVE you an amp (just cover the cost of shipping) but your disrespectful comment has taken that offer off the table.

Nobody tells me or anyone else what threads to participate in, how to answer or who to ignore. The advice given is for everybody who might read this thread, and I stand by my comments as being accurate.

 

[KJMO]

Honestly, how can you beat the TC stuff or that Harley Benton thing for value? If you want to DIY, find a quiet fan with the correct specs to swap in. People do that all the time, but you got to have the right flow.

 

[yodedude2]

FYI: I used to use an Acoustic Image?
2 channel, 1000w at 2 ohm version.
...
It shut down twice at an outdoor gig, running at 8 ohms on a 90 degree summer gig under a large tent.
Luckily, the person throwing the party was able to give me a fan to keep the amp running for the rest of the gig.

in case any a.i. folks are following along...long ago i used to have trouble with a.i. amps engaging their protection circuitry and shutting down when playing outdoor day gigs in hot, humid, muggy, sunny south texas. i soon discovered that if the amp were in the shade, any shade, it would not shut down; but, if it were in direct sunlight, eventually it would. keeping the amp in the shade continually prevented any further issues.

 

[road-cat1]

Rare Stewart Power Amp CA400 | eBay
STEWART power amp. I regret that I sold mine. It is fanless and is top level pro equipment. This one on EBAY is $200

 

[fdeck]

I went down the DIY power amp road many years ago, and in fact, gigged with a completely homemade combo amp for many years. It put out 60 Watts. I had the benefit of access to some surplus electronic parts including a power transformer and a pair of National Semiconductor LM12 power op amp chips, which I wired in bridge mode. Talk about overkill.

One day, as I was setting up for a gig, my amp tripped a GFCI. The sound tech pointed me to an unprotected outlet, and I played the gig. I told my spouse about it.

Spouse: Don't they make amps that you can just buy?

fdeck: Sure, there's that nice little GK combo.

Spouse: Why don't you just go and get one?

fdeck: Okee dokee!

I checked out my amp, and there was nothing wrong with it. Also, I later heard that every amp trips the GFCI in that venue. Still, I was gradually moving into higher profile gigging, and didn't feel that I should impose my gear hobby on my band-mates. Plus, I didn't want to become the guy whose homemade amp crapped out on a gig. I trust myself with small-signal electronics, but when it comes to stuff that plugs into the mains and controls large amounts of energy, I prefer letting the big kids design that stuff today. Also, my brain cells are enough to grasp Class-AB, but I don't think have any hope of actually designing a decent switchmode amp.

Since I still enjoy keeping an eye out for things, my assessment is similar to what others are suggesting, that your best bet is an IcePower module, and the best way to get an IcePower module is inside a commercial bass amp. For "power amp" use, you can either plug into the effects return, or just dial the preamp to a neutral setting. Class-D amps are efficient, but not 100%, and there's a big difference between fanless and even just a tiny amount of airflow. For this reason, the units with a 2 speed fan are likely to be inaudible in typical home use, but the full power can kick in if conditions demand it.

 

[Black Out Jazz]

The best Class D mini bass amps | Guitar World

 

[frankie5string]

This thing looks great - a lot like the Trace Elliot Elf that kicked off this line of thinking. I love the idea of slipping a bass head in my pocket.

You probably won't actually like the Elf. Its fan actually rides along with your playing. It whizzes up and down maniacally if you're playing the amp at anything above low volume. Some of the TC micro-amps do that too.
Once you stop playing, it winds down to a quiet purr. I love it because of its size and its sound, but I don't have a problem with fans.