Just in Nobsound NS-01P Pre-Amp

kcline

Tube Audio Collector
Had a big discount from Amazon to use so I bought the first new preamp I have bought in over 30 years. Tube sockets are so tight I cannot get tubes all the way in but they do light and work. Connected it to my Fisher SA-100, Xp-10 speakers and a cd player that I use for testing. Let pre warm up for an hour then turned amp on. Sounds good but did not listen for long. With CD in pause and gain up all the way it had no noise or hum. Hope to play longer this weekend.
 

Attachments

  • DSCN2628.jpg
    DSCN2628.jpg
    66.8 KB · Views: 396
  • DSCN2626.jpg
    DSCN2626.jpg
    69.3 KB · Views: 391
I have one... If you plan on tube rolling, do this (PITA), remove bottom plate and hold board with fingers use other hand to insert tubes.

BTW-- IMO, this pre with good tubes punches way above its weight/price class
 
Thanks for replies I did not play the pre. this weekend, I hope to get back to it soon. Taking off the bottom and holding the board to get the tubes in? I will try down the road, for now I will let unit play with the stock tubes
 
Had some time today so I took off the bottom plate and pressed against the board to get the tubes fully in the sockets, thanks Frank Sol for the tip. I also took some pictures of the inside. EnjoyDSCN2636.jpg
PS is that a real Alps control?
DSCN2637.jpg

DSCN2641.jpg
 
I am still listening to this pre. Right now I have placed it and the Fisher SA-100 in my "kitchen" rack. I have maybe 10 hrs on the pre so I guess it is still braking in. Here are a few pictures on the rack and other gearDSCN2646.jpg

DSCN2644.JPG

DSCN2647.jpg
 
Had time very early today before I go to work, to listen to this pre and the Fisher SA-100, XP-10 speakers combo with the test CD player a DBX-DX-5 for about 2 HRS. The pre is burning in nicely I am still using the stock tubes it came with. Played Simon & Garfunkel Bridge Over Troubled Water Mastersound Gold CD twice, sound opened up after the 1st hour and this CD sounded much better the 2nd time thru.
 
Any more impressions on this pre? Im thinking of using one to drive a Crown XLS amp. I dont see many reviews online, other than Amazon. But knowing people get paid to post good reviews there, Id like to see others.
 
I have played the pre for a few more hours and it does sound good. I have been playing a Little Bear phone pre through it and the Fisher SA-100, XP-10 speakers combo, I get a nice wide sound stage and good highs and lows. I am happy with sound and I am still using the stock tubes
 
Found this thread today. I just purchased this preamp and have it connected to a cheapy chinese power amp at the moment with a Dayton APA100 power amp due to arrive in two days.

This is my first foray into tubes and I did not know what to expect. My prior system was a vintage Sanyo receiver which had decent sound.

But after connecting up this new setup with the Nobsound preamp, wow. The bass seems to be greatly enhanced. Is that to be expected? The width of sound stage (or am I talking imaging?) is fantastic. Is that to be expected?

I am running a pair of Infinity RS 5b's and they sound superb.

As mentioned, the tube sockets are pretty tight and care MUST be used when inserting them.

Here's a question I've asked elsewhere: To get the most out of this preamp and its "tube sound," how should I deal with the three volume controls that my system now has? There's the Chromecast Audio volume control, the power amp volume control, and the preamp's volume control.

Should I max out the preamp's volume control? Or not?

Since I'm new to tubes, some clarification on these volume controls would be most appreciated. Elsewhere on AK, I've gotten comments about "unity gain," but am pretty much lost in that discussion.

Thanks!!
 
I got the Nobsound NS-01P preamp a few months ago and really like it; it's a huge bang for the buck. But I didn't like the stock Shuguang tubes, too bright + not enough headroom = harsh when you crank it. I got current stock Russian Tung-Sol 12ax7 (much better and about $15 apiece) but the pins are fatter than the Chinese tubes and were even worse to get into the Chinese sockets. So I went with gold plated socket savers off Ebay from China for about $5 apiece. The pins on those went into the sockets reasonably (I did brace the board from behind with rubber gloves -- watch out for those respectable capacitors, they lit me up a little even after powered off a few hours), and the fat-pinned Tung-Sols went into the saver socket very reasonably also. This sets me up for as much tube rolling as I could want; since the tube savers are larger in diameter than the holes in the case, the board is not bent by inserting tubes, and I just have to grip the tube savers when pulling one out.
 
Also the Nobsound NS-01P has a nonstandard rectifier and socket, a 6z4 and Shunguang tube. I wanted to upgrade this also (maybe unnecessarily), apparently the difference between a 6z4 and a 6x4 is just pinout, and so I found a 6x4 (top) to 6z4 (bottom) adaptor from China also, ordered that and a vintage 1958 Tung-Sol 6x4. Both are on their way, but I just found out from Douk Audio that the power circuit is fixed-biased, not self-biased.

It probably sounds like I know what I'm talking about by this point, but I assure you I don't. I'm kind of groping around, and here's where I need help. From reading around, my understanding is that if it were self-biased I could just pop in the adapter and replacement, but since it's fixed biased it kind of depends on the tube, or something, and I have to figure that out.

Am I wasting my time on the rectifier? I should say I have the Nobsound plugged into an Adcom A/C enhancer anyway.
If I'm not wasting my time (and anyway the bits are on their way so I may as well use them), what do I need to be concerned about? Any advice?
 
Oh and here's a circuit diagram of the Nobsound NS-01P from Douk Audio.
 

Attachments

  • NS-01P.pdf
    103.7 KB · Views: 133
@hnash53: I've always heard that you max out the amp then bring up the pre-amp, and I would assume you would want your input to be about normal line-level. But I'm new to tubes too. Also my amp doesn't have a volume control and will put out 200w/ch so if I take my NS-01P up nearly halfway I start sweating about my speakers.
 
image.jpeg Saw this nice looking one and it took me a while to find the model number and this thread. I'm creating a space for one!
 
I have had one now for a couple weeks. It's hooked to a Mac mc7100 and Martin Logan speakers. The tubes need changed first... don't even bother till you do...lol. I am using Amperex ax7's with great results. the new 12ax7LPS are what I would use if buying new. I am slowly burning her in. She has a lot of gain so I "may" go to a AT7 or AU7... this pre is very clean and seems to be built well. I will chime in on tube rolling as i go thru the process. I would recommend this as it is very cheap (i paid 154$) and sounds great.
 
I changed my tubes several times and have the nos Beijing Shuguang square foil getter tubes. These sound brilliant better than the new Shuguang tubes, can anibody tell me what the 3rd tube does? The two right tubes are for left and right channel but the left tube does something else and glows up different than the other two. I replaced the rectifier tube with a russian nos 6C4P-EV this tube just slots in.
 
Last edited:
Back
Top Bottom