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Cheap little integrated amp kit

This is the DIY sub forum after all, so sure a guy could just BUY a NAD 3140, or whatever, but that's not really the point, eh?

But yeah - please feel free to recommend me a 'good quality kit' that has the following features:

Preamp with tone and balance controls
Small-ish footprint - somewhere around 8" wide
Don't care about about power level - 5-10W is all I need, or preamp only and I'll add the PA myself.
No desire for tubes
No need for a phono input
 
Speaking of regulation, most of the amps I've seen don't use regulation and depend on the PSRR of the chips/circuit design to keep the power supply fluctuation out of the speakers.

I'm not sure if I ended up getting a fake STK4191 (likely, however) but I used it to replace a broken STK module. As far as I could tell, it still could dump out 20+W just fine, sounds OK, and didn't burn up. I just don't have the equipment to really test it to 50W and full distortion specs. Not sure what my neighbors would do if I simply turned it up to 11... All moot now, it's gone now anyway.

These STK amplifier modules are pretty much amplifiers-in-a-box. Not much can go wrong with them, just don't mess up assembling the kit and don't forget to stick them on a suitable heat sink, and they should work just fine. A quality transformer of the right voltage and current rating is needed.

I'd be curious to see what's in the fake STK chips. They were always hybrids, so I would never expect to see a monolithic chip in them. As long as the circuit performs as good as what they're replacing, it's a black box, I don't necessarily care what's in them. But fakes are fakes and don't do what they're supposed to do...
 
Brickbat said:
This is the DIY sub forum after all, so sure a guy could just BUY a NAD 3140, or whatever, but that's not really the point, eh?

But yeah - please feel free to recommend me a 'good quality kit' that has the following features:

Preamp with tone and balance controls
Small-ish footprint - somewhere around 8" wide
Don't care about about power level - 5-10W is all I need, or preamp only and I'll add the PA myself.
No desire for tubes
No need for a phono input
Click to expand...

There is a preamp only kit based on a NAD discrete circuit...looks pretty decent. I also have a couple of NE5532 IC based preamp kits on the way. Here’s the NAD-based kit: https://www.ebay.com/itm/DIY-Fully-...e-On-UK-NAD-Preamplifier-R175-9-/122512222320 I’m pretty sure one of these will work as a front end for the ST70/ST120 I intend to build one of these days soon.
 
I have a VTA ST-70 I built last year. Other than needing a phono stage for records, a passive preamp with input selectors will work if you don't want tone controls. I did replace the mono/stereo switch with a stepped attenuator on the ST-70. Most sources like CD player, tuner, tape machine, ect. Have plenty of gain to drive the 70's and 120's. I am running an Aikido tube line stage and moddified Dynaco PH-10 phono board with my ST-70. Also look into active tone control kits. I built one of these kits using one dual triode per channel and it sounds pretty nice. I also added a relay controled selector. It didn't have the higher gain of other 10x preamps and doesn't tend to easily overdrive the amplifier. But adding the attenuator option on the ST-70 is handy for controling the input signal.
 
mv213 said:
There is a preamp only kit based on a NAD discrete circuit...looks pretty decent. I also have a couple of NE5532 IC based preamp kits on the way. Here’s the NAD-based kit: https://www.ebay.com/itm/DIY-Fully-...e-On-UK-NAD-Preamplifier-R175-9-/122512222320 I’m pretty sure one of these will work as a front end for the ST70/ST120 I intend to build one of these days soon.
Click to expand...
I bought one of these type kits a couple years ago. Around $20. It has volume, balance, bass, midrange and trebble controls using NE5532 chips. Pretty amazing sound from that little board connected to a 12 volt transformer.
 
Lavane said:
I bought one of these type kits a couple years ago. Around $20. It has volume, balance, bass, midrange and trebble controls using NE5532 chips. Pretty amazing sound from that little board connected to a 12 volt transformer.
Click to expand...
Good to hear that, I hope one of the two NE5532 kits I have coming will work well enough to use.
 
Lavane said:
I bought one of these type kits a couple years ago. Around $20. It has volume, balance, bass, midrange and trebble controls using NE5532 chips. Pretty amazing sound from that little board connected to a 12 volt transformer.
Click to expand...

The item you linked to has no balance control. I'd be curious to find out exactly what you bought - it sounds like what I'm looking for...
 
Brickbat said:
The item you linked to has no balance control. I'd be curious to find out exactly what you bought - it sounds like what I'm looking for...
Click to expand...
I was just referencing the OP's post. Mine was very similar. I'll see if its still available. It was a ChiFi kit from a couple years ago.
 
Brickbat said:
The item you linked to has no balance control. I'd be curious to find out exactly what you bought - it sounds like what I'm looking for...
Click to expand...
Both of the NE5532 kits I ordered have midrange but no balance control....so no good for you?
 
^ yeah - seems like a balance control would be more useful than a midrange...

Lavane said:
...This one claims to use jfets. They should be pretty quiet. I don't know anything about the tone chip used though. ...
Click to expand...

I'll take a look - thanks!
 
I received one of the NE5532 preamp kits late last week and soldered it together Sunday. Today I took the time to hook up a power transformer, audio source, and connect it to the AUX jacks on my Pioneer SX-727. At first I thought it wasn’t working because even with the receiver volume all the way up I heard nothing. But it was working, it just wasnt adding much noise. I gradually increased the preamp volume and it sounds actually pretty good. All the controls and the power LED also work well. Next step will be to connect it directly to the “main in” jacks on the Pioneer and test gain and so on. I’m pleasantly surprised at this point, to say the least. I have some pictures but can’t post them from here.
 
Mandy Barnett sounded great on ‘Planet of Love’ and ‘Sweet Dreams’ through this little guy driving my SX-727 thru the main-in jacks. These are pretty high bit-rate rips. Seems to have enough gain and sounds good. This was the first of two cheap preamp kits I ordered. The second hasn’t arrived yet. I’ll probably pick up a cheap enclosure and add a source selector and call it good.

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Nice work. Mine hasn't shown up yet. I'm glad to hear it's quiet w.r.t. background noise level. A 5532 ought to be decently quiet...
 
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Ive used two of those relay selectors with good results. Very quiet. Plus the LED's can be moved off the board to a front panel. The first one I bought came with a very cheep selector switch, all plastic. So when I bought a second one I made sure it had a better switch. The ones without jacks on the board are better I think. That way you can use the board in a case of your choice.
 
Lavane said:
Ive used two of those relay selectors with good results. Very quiet. Plus the LED's can be moved off the board to a front panel. The first one I bought came with a very cheep selector switch, all plastic. So when I bought a second one I made sure it had a better switch. The ones without jacks on the board are better I think. That way you can use the board in a case of your choice.
Click to expand...

Do you have a link to one that you recommend? I’ve seen a few on eBay and wondered if they were any good. Also i have an enclosure, knobs, and jacks coming. I hope to have this thing finalized in the next few weeks (limiting factor is mainly the time for cheap shipping from China).
 
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