I am thinking of buying the Nobsound 6p6p+6j8p so I can have some fum tube rolling and making some upgrades.
I can get it on Europe for 220€ delivered I think is less than the price of the components.
Anyone as experience with this model?
HiFi 6P6P Valve Tube Power Amplifier Stereo Class A Single-ended Home Audio Amp | eBay
I can get it on Europe for 220€ delivered I think is less than the price of the components.
Anyone as experience with this model?
HiFi 6P6P Valve Tube Power Amplifier Stereo Class A Single-ended Home Audio Amp | eBay
No exp. with that amp. You realize it's only 4 watts/ch., with a tailwind.🙂
Lots here seem to like the Boyuu EL34 amp.: Boyuu EL34 A9 Tube Amp
jeff
Lots here seem to like the Boyuu EL34 amp.: Boyuu EL34 A9 Tube Amp
jeff
My experience with those output transformers is that they will pass about 1/4 of a watt at 35Hz. My experience with Nobsound is that they will use bottom quality components (fake caps among other things).
220 Euros could get you acceptable iron and a cake pan, you are on a DIY forum after all!
Tube rolling won't fix the issues the Nobsound product has.
220 Euros could get you acceptable iron and a cake pan, you are on a DIY forum after all!
Tube rolling won't fix the issues the Nobsound product has.
This amp redefines the meaning of low end.
It has no riaa, it has only one input , it has no tonecontrols what so ever
and it does not even live up to the old german "HiFi" standard that demands
at least 10w per channel in the full 40 - 15khz span.
In addition it has no schematics and no source of spares is given.
But it's your money. Throw them away, feed the chinese industry!
I have direct experience on other low-end tube amplifiers from this seller. This kind of low-end amplifiers seems a bargain at first, but they are not. I would avoid the NS-03D kit because the chassis is poorly made: the filter choke is directly beneath the left output transformer, and the sides are made of wood. There will be background hum and noise. The NS-02D amplifier (5Z3P+6H9C+EL34B) is basically the same circuit but with better transformers and a bigger chassis. Output power is almost exactly half as advertised. Power transformer is never CE/UL compliant. Compare prices carefully because it is sold by several sellers, but even with discounts, there is still a premium over a DIY build with slightly better transformers. I bought my NS-02D as "damaged" customer return from Amazon, and I paid 40% of the original retail price, so a lot less than the price of the amplifier referenced on post #1. It does come with EL34 tubes but it does have a tiny power transformer, smaller than the one fitted in vintage stereo Saba radios from the '60 with noval tubes. It performs poorly on stock configuration and I had to do several circuit modifications and use smaller output tubes. That would have been a very poor purchase choice at the original retail price.
This is a great detailed feedback thanks for sharing it.
Fron what i can see the NS-02D it's probably almost identical to this, they even say that you can fit the EL34 on this without modification.
Last edited:
Could you be so kind to share the modifications, I am already targeting a "Amazon Used".
Attachments
As he said, the iron isn't great, the chassis is flimsy, and the components are of poor quality.
So you're paying 200+ Euros for some tubes you can use when you build something less terrible.
So you're paying 200+ Euros for some tubes you can use when you build something less terrible.
They'll say pretty much anything for a sale. For some reason, you seem to have your heart set on this amp.🙁
jeff
I paid less than 200 euro, but on my specimen the base of one EL34 had a broken spigot due to rough handling by the previous owner. The EL34 tubes are not matched, but they are both working fine. On the picture you see the parts that I had to exchange immediately. Leaky, recovered Wima coupling capacitors and the toasted EL34 cathode resistors. The black/red low voltage speaker wire was connected to the 230V mains power switch. The short black wire was soldered to safety ground mains power connector. I think you may already get a picture of the quality level of this build. See the output transformer wiring for more hints - no grommets were fitted of course. The long, untwisted black wire was for the heaters. It was neatly tucked underneath the terminal strip board and was a contributing cause of hum, togheter with a ground loop that I removed by rerouting and shorting the blue wire (signal ground). The manufacturer tried to solve the obvious issue by increasing to 220 uF the first filter capacitor: it was directly connected to the rectifier tube, before the 4H choke. I was amazed to see no arcing inside the rectifier. The B+ value with the factory 5Z3P rectifier tube was 310V; it is 340V now with a GZ34 tube and a 33uF capacitor. I then made further modifications, but the amplifier was at least working at this stage.
Attachments
I am perplexed with the build quality, are you sure you didn’t buy a DIY kit that was assembled by the previous owner?
Did you try the 6v6 tube?
SoundZen,
Something you said caught my attention:
"I can get it on Europe for 220€ delivered I think is less than the price of the components."
Whenever you look up the prices of all the components, it is always more than the price of the assembled product.
Go to your Automobile Service Center, and get the prices of a Motor, Transmission, Air Conditioner, etc.
Did the prices add up to more than a new car?
Something you said caught my attention:
"I can get it on Europe for 220€ delivered I think is less than the price of the components."
Whenever you look up the prices of all the components, it is always more than the price of the assembled product.
Go to your Automobile Service Center, and get the prices of a Motor, Transmission, Air Conditioner, etc.
Did the prices add up to more than a new car?
Not the same amp-
I purchased Nobosound 6P1 / 6F2 P-P 12W amp as DIY kit last April.
Initial sound impression was very flat through Brit Cambridge Audio Minx XL's, which are good bookshelfs- IMO. Added silicon preamp / tone control on front end, which helped. 'Rolled tubes' of moderate cost using US and Russian versions of original. Found original ChiFi tubes were best w/ for low noise, but 6U8's better for sound quality. Supplied parts did include WIMA coupling caps as posted earlier, 5k output transformers.
Not unhappy w/ this product- bought it for ongoing design change platform. My advice if you buy ChiFi- get DIY kit to control proper assembly, based on what was posted earlier... otherwise, go over work w/ fine tooth comb.
Best,
Jim
I purchased Nobosound 6P1 / 6F2 P-P 12W amp as DIY kit last April.
Initial sound impression was very flat through Brit Cambridge Audio Minx XL's, which are good bookshelfs- IMO. Added silicon preamp / tone control on front end, which helped. 'Rolled tubes' of moderate cost using US and Russian versions of original. Found original ChiFi tubes were best w/ for low noise, but 6U8's better for sound quality. Supplied parts did include WIMA coupling caps as posted earlier, 5k output transformers.
Not unhappy w/ this product- bought it for ongoing design change platform. My advice if you buy ChiFi- get DIY kit to control proper assembly, based on what was posted earlier... otherwise, go over work w/ fine tooth comb.
Best,
Jim
Attachments
Last edited:
The amplifier was inside the factory package and all the solder joints were covered with a spot of white silicone to discourage tampering, so it was a factory build I presume. I cannot be sure because it was a open box item. I tried 6F6 tubes (VT175 actually); to use this tube the cathode resistor value must increase, and input stage should also be modified to get more gain.
And how were the words "Nippon Chemi-con" spelled on the power supply caps that came with it?
And how were the words "Nippon Chemi-con" spelled on the power supply caps that came with it?
Not sure markings on those caps; Amp is disassembled at my shop- will check
Jim
Not sure markings on those caps; Amp is disassembled at my shop- will check
Jim
Letters on 330uF / 450V power supply caps reads: NAPFCM CEBNVCON. I can see 'Nippon Chemicon' in those words if I squint- lol
But perhaps someone this forum familiar w/ russian or eastern eu spelling can explain better.
Initially, was a bit confused by reference to 'Nippon' in context of china Q. Always thought that was reference to Japan. But then I researched Nippon- China.... Interesting- but not surprised.
Jim
Yeah, so those are counterfeit trash caps. They can't even spell the the words properly when they make their copies, would you trust them to be able to properly make an electrolytic cap?
I intend to use these until they expire- if their colorful expiration causes the smell of popped electrolytic to permeate the air in the room which they reside, then... we will have more for this forum😀
Jim