Hey just saw eBay promoting this tube bluetooth and analog integrated amplifier.
Wondering what you think?
Price is $150w/ free shipping in USA? (note- not $179 (sorry about the title of this thread) but $150)
Regular price is $300, so its "on sale"
Yes I assume its cheap and from china, but it actually looks pretty neat.
Link-
392187141147 | eBay
Note- not affiliated in any way with this stuff!
I am wondering if the tubes are for show or actually hooked up, and whether there are actually 3 transformers under that big back section, or if its a tiny chipamp or class D dealie.
But $150....its almost worth a look.....
Wondering what you think?
Price is $150w/ free shipping in USA? (note- not $179 (sorry about the title of this thread) but $150)
Regular price is $300, so its "on sale"
Yes I assume its cheap and from china, but it actually looks pretty neat.
Link-
392187141147 | eBay
An externally hosted image should be here but it was not working when we last tested it.
Note- not affiliated in any way with this stuff!
I am wondering if the tubes are for show or actually hooked up, and whether there are actually 3 transformers under that big back section, or if its a tiny chipamp or class D dealie.
But $150....its almost worth a look.....
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Maybe the tubes are for the input section only and there is a cheap solid state output of some type? Weight is 6.6 lbs, a little low?
Edit- just saw something similar at monoprice
Monoprice 25 Watt Stereo Hybrid Tube Amplifier with Bluetooth - Monoprice.com
Monoprice says its 'hybrid' with a class AB solid state output.
Article in the Wall Street Journal-
The Miracle of a $150 (or Less) Tube Amplifier - WSJ
Edit- just saw something similar at monoprice
Monoprice 25 Watt Stereo Hybrid Tube Amplifier with Bluetooth - Monoprice.com
Monoprice says its 'hybrid' with a class AB solid state output.
Article in the Wall Street Journal-
The Miracle of a $150 (or Less) Tube Amplifier - WSJ
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That's the one. Started out as the Monoprice, and was (and still is) available with at least six different names on the front. All the same hybrid class AB output stage with tubes up front, running low voltage. I've seen pics of the earlier version with a chip amp for the outputs, and later ones with discrete BJT outputs. They eventually added bluetooth and then usb on the front. Here's one with a different name: YouTube
jeff
jeff
One year later - there are several variations of this same amp on Amazon. There have been some feature updates - most of them seem to have a USB port on them, one has a TOSlink input. All seem to run around the $160-$170 price point.
If you go to the Monoprice link in the third post above, the original unit is now on sale for $99. I just had to pick one up at that price
. It may get minimal service time before I pull it apart and start modding. Should be interesting to see if it's possible to tap the preamp output and drive some other backend with it. Hmmm... ;-)
Has someone opened one up yet?
-bill
If you go to the Monoprice link in the third post above, the original unit is now on sale for $99. I just had to pick one up at that price
. It may get minimal service time before I pull it apart and start modding. Should be interesting to see if it's possible to tap the preamp output and drive some other backend with it. Hmmm... ;-)Has someone opened one up yet?
-bill
I think I just got a whiff of the steaming heap, myself.
Bill, if you mod it, please post some pics. I'm dyin' to see under the hood, too. All I can say is that they might have chosen a better name.
Let's see...
- VU meter? Check.
- Chrome-encrusted tubee-cagee-thingees? Check.
- USB/Bwoo-toof/Whatever? Check (sorry, I've been watching Blazing Saddles).
- A claimed power output that exceeds the bounds of physics for the tubes shown? Check-a-mundo.
- Weird-looking hump posing ostensibly as transformer cover? Check-o-rama (how much you wanna bet it's a heatsink?).
- Advertising claims that would raise Leonard Doob from the grave? Check-a-roonie-o.
But wait - there's more!!!
The only thing that would raise this to absolute awesomeness is blue LEDs beneath the tube sockets. Yes!
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1. At 6.6 lbs, you might be able to get 70 Watts per channel out of a class D amplifier.
2. Under most international law, the shipping weight of any package going from one country to another needs to be quite accurate.
What is the shipping weight?
If the weight is wrong, contraband is suspected. It will not be delivered to the customer (unless the local customs and law agents are closely watching the customer).
3. 6.6 lbs., or 6.6 kilos?
Well, kilos has a certain connotation.
Good luck!
2. Under most international law, the shipping weight of any package going from one country to another needs to be quite accurate.
What is the shipping weight?
If the weight is wrong, contraband is suspected. It will not be delivered to the customer (unless the local customs and law agents are closely watching the customer).
3. 6.6 lbs., or 6.6 kilos?
Well, kilos has a certain connotation.
Good luck!
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6A3, I'll bet you're right about Class D. It's entirely possible in the size shown. It's just the way it's presented that gives me pause. For instance:
Tube Amplifier / Receiver
- True enough, provided that the tubes are doing the amplifying (at least as an input stage) and if what's being received is a Bluetooth signal.
Tube amps do not hard-clip even at high volumes and are extremely efficient [emphasis mine]. Due to this the amp sounds more like double the rated power!
- Uh, yeah... The hard-clipping thing is generally true, but extreme efficiency isn't a hallmark of tube amps. As to the whole "double the rated power" thing, I'll let others judge...
Built in Bluetooth with 33 foot range
- A 33-foot range isn't really a "feature", but about on par with normal Bluetooth specs.
USB can charge your phone or other USB device
- Quite true - as long as your device doesn't draw more than 0.5 A.
Total Harmonic Distortion(THD): =0.02%
- At what frequency, what power output and at what load? Yeah, there's probably a class D amp involved.
Now I'm not saying this is a bad deal - indeed it may well be a hidden gem - but it's up to the buyer to do his/her homework and apply a little critical thinking. Anyone purchasing one of these with an eye toward modification probably has a clue as to what they're getting. Caveat emptor.- True enough, provided that the tubes are doing the amplifying (at least as an input stage) and if what's being received is a Bluetooth signal.
Tube amps do not hard-clip even at high volumes and are extremely efficient [emphasis mine]. Due to this the amp sounds more like double the rated power!
- Uh, yeah... The hard-clipping thing is generally true, but extreme efficiency isn't a hallmark of tube amps. As to the whole "double the rated power" thing, I'll let others judge...
Built in Bluetooth with 33 foot range
- A 33-foot range isn't really a "feature", but about on par with normal Bluetooth specs.
USB can charge your phone or other USB device
- Quite true - as long as your device doesn't draw more than 0.5 A.
Total Harmonic Distortion(THD): =0.02%
- At what frequency, what power output and at what load? Yeah, there's probably a class D amp involved.
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There may be a little confusion here. The amp specs (at least the one shown on the Monoprice page that I just purchased) indicate that the tubes are for the preamp stage only and the back end is solid-state AB (I'm figuring probably a chip amp, but could be discrete).
Some of the confusion stems from the fact that these amps are being marketed under several different brands and there seems to be several generations of them. All share the same same basic chassis. The model that is on sale at Monoprice appears to be one of the earlier ones. It does not have USB input, no TOSlink and only a single line level input plus Bluetooth.
The pics on the site show something sitting underneath the plastic box (ooOOoo... "mystery components" ) . One of the YouTube videos I found showed someone disassembling the Rockville version (shown in the first post) and indeed there was nothing in the box - all of the backend amp components had been moved onto a single board inside the main chassis.
Another video showed that the VU meter was actually worse than useless - needle never made it past half scale no matter how high the input level was.
But, but, but... it's SHINEY and has tubes that actually GLOW and a meter that moves and it's CHEAP, and I may gut the entire thing eventually but if I didn't have it I was just going to DIE!
I'll post some pictures and a summary once I receive this one.
-b
Some of the confusion stems from the fact that these amps are being marketed under several different brands and there seems to be several generations of them. All share the same same basic chassis. The model that is on sale at Monoprice appears to be one of the earlier ones. It does not have USB input, no TOSlink and only a single line level input plus Bluetooth.
The pics on the site show something sitting underneath the plastic box (ooOOoo... "mystery components"
) . One of the YouTube videos I found showed someone disassembling the Rockville version (shown in the first post) and indeed there was nothing in the box - all of the backend amp components had been moved onto a single board inside the main chassis.Another video showed that the VU meter was actually worse than useless - needle never made it past half scale no matter how high the input level was.
But, but, but... it's SHINEY and has tubes that actually GLOW and a meter that moves and it's CHEAP, and I may gut the entire thing eventually but if I didn't have it I was just going to DIE!
I'll post some pictures and a summary once I receive this one.
-b
Attachments
The amp has arrived. Actually the second one. First one arrived with one of the tubes cracked. Funny that in the users manual they indicate that the tubes will be wrapped separately and will need to be installed by the user (no big deal, right?). But it seems that they install them prior to shipping with the expected results. They insisted that I had to send back the entire unit (RMA, they covered shipping), rather than just having them send me a replacement tube. Serves me right because I mentioned that I thought that the whole side was out - didn't realize that the tube emitters were wired in series on each side and one tube would not light without the other in the socket...
Pics will follow soon, but I've opened her up and here is what we find (for this model):
1. The black plastic box on the top rear conceals a nice little toroidal xformer. I haven't had a chance to put a DMM on it to find the rail voltages.
2. The power amp circuit is indeed a chip amp based around a pair of LM1875's. The board seems reasonably laid out.
3. The VU meter is, indeed, useless.
4. There is a bit of a pop on one channel when it powers up. The first amp did not exhibit this behavior. Will need to check out.
5. The speaker posts on the back are truly a cheap POS. Won't hold a banana plug securely (just rattles around)
6. Bluetooth seems to work well - paired easily with my MacBook.
7. The amp gain seems a little low - I have the volume knob at full scale with the laptop output at around 60% over bluetooth and the output is definitely a bit lacking (and this is with 4-ohm speakers)!? Output is no better/louder with a direct connection to from the headphone jack to the RCA inputs.
For the money, it's a fun little toy to play with. Currently listening to a little Al Stewart right now. Vocals are good, high-end seems a little rolled off.
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