[Dan-Fi]

Thanks very much for the response and good to know that LT1364 works well in this amp. I have used LT1028 and LT1057 op amps in my cmoy and agree that they sound more refined than the BB's I've tried, such as 2107 and 2111. As you said, OPAs do have a darker (but to me only slightly) sound than the LTs, which works for my SR325is and even my AKG K145/s, the latter of which I think is the harsher sounding of the two in treble. I'm only using 2107 over the stock op amp as that is the only one in my stock where I have a pair of that works
 
Current problem I'm having is with the power supply that came with the amp, or possibly with the power socket, as I'm hearing a background hiss every now and then. But if I wiggle the power jack, the hiss does disappear, as long as I don't move the cable again! I've ordered another 6VDC/2A power plug to see if a loose jack is the cause of the problem.

 

[edulov]

Faced noisy PSU problem, but in you case, I think you have to clean up contacts in the wall outlet first. Most people don't pay attention that some metal alloy is not so resistant to oxidation or become covered with thick ash after small electric sparks inside if there is a bad contact with plug. But be careful, cut off the main switch first.

 

[Subhakar]

 

 
 1. I ordered Nobsound 6J9 from this link: https://www.aliexpress.com/item/Music-Hall-6J9-Vacuum-Tube-Integrated-Amplifier-Mini-Audio-HiFi-Stereo-Headphone-amp-DIY-Free-Shipping/32443111524.html?spm=2114.13010608.0.0.RQn3jj
Is it fully assembled one or a tedious DIY?
 
2. The stock opamp this one comes with is half decent at least? 
 
3.  Which tubes do you suggest for replacing the stock ones with?! I can spend a maximum of $10 on each. I am using them with beyerdynamic DT 990 (600ohm). I like neutral and analytical studio-like signature with a little bit of bass and a great soundstage LxWxH that is possible.
 
Thanks.
 
 

 

[Brian Coffey]

 1. I ordered Nobsound 6J9 from this link: https://www.aliexpress.com/item/Music-Hall-6J9-Vacuum-Tube-Integrated-Amplifier-Mini-Audio-HiFi-Stereo-Headphone-amp-DIY-Free-Shipping/32443111524.html?spm=2114.13010608.0.0.RQn3jj
Is it fully assembled one or a tedious DIY?

2. The stock opamp this one comes with is half decent at least? 

3.  Which tubes do you suggest for replacing the stock ones with?! I can spend a maximum of $10 on each. I am using them with beyerdynamic DT 990 (600ohm). I like neutral and analytical studio-like signature with a little bit of bass and a great soundstage LxWxH that is possible.

Thanks.

I purchased mine from the same store and have been very impressed with it so far. I replaced the original tubes which I didn't think sounded all that bad with NOS Amprex 6688a. There was a fair amount of improvement in range and tone. The amp itself is fully assembled except for inserting the tubes.

 

[Subhakar]

I purchased mine from the same store and have been very impressed with it so far. I replaced the original tubes which I didn't think sounded all that bad with NOS Amprex 6688a. There was a fair amount of improvement in range and tone. The amp itself is fully assembled except for inserting the tubes.

Thanks. Any particular site I can buy NOS Amprex 6688a from? Preferably in India/Asia? Can't find one locally.

 

[Brian Coffey]

Thanks. Any particular site I can buy NOS Amprex 6688a from? Preferably in India/Asia? Can't find one locally.

Sorry I got mine from Ebay here in the US.

 

[Prohobo]

I just ordered one of these little amps for my HE-400s to hook up to my computer at work.
 
This will be my first TUBE amp and I also ordered a set of these tubes, any thoughts?
 
https://www.amazon.com/gp/product/B0002M72JS/
 

Electro-Harmonix 12AX7EH Preamp Vacuum Tube

 
 
Of course I am a newbie - so I welcome suggestions.

 

[Headphone4Life]

They should be fine. Lets us know how it sounds with the 400s. I thought this little amp sounded better with my dynamic headphones more than with my HE-400i. Even though I don't use this amp anymore I hooked up my Focal Elear and it didn't sound half bad.

 

[edulov]

Sorry, but these are incompatible.
You need one of those:
5A/170K
6j9p (6ж9п)
6688
CV3998
CV6189
E180F
EF861
EF180
 
If you order any valves untested, get 3 and select by ear a pair which provides balanced sound for L/R

 

[Prohobo]

jajajaja
 
So there is a reason they call this amp NOBsound - I guess I am the NOB?!?!?!
 
 
I was told these tubes:
 
E180F, EF861, 6688, 12AX7

 

[edulov]

Valve compatibility is not a secret. Even on eBay, you will find correct cross-references trying to search for 6j9p (6g9p), both are the transliteration of a Cyrillic letter "Ж". I know about one another 100% electrically compatible lamp, but dunno how it sounds, still planning to try it on. Also, there are some more from the same "family" 6ж, partially compatible.

 

[cam94z28]

Just got this little amp, and I'm already amazed!
 
I've always had a "problem" with my ears, where either mine are more sensitive than everyone else, or they are about 10x more sensitive to sibilance, and "beaming" mids than most people. To the point that there is a physical reaction in my ears (mostly the left) to sibilant peaks. This amp might be the holy grail, in my case.
I have been listening to my most sibilance prone headphones, and some known-sibilant songs. It's like this amp picks the sibilant ranges ONLY and smooths them over, without having much of an effect on the rest of the range. Is this the tube sound that everyone is raving about? If so, I'm a believer! I have a Schiit Vali (series 1), and it doesn't smooth the sound over like this. Maybe part of it is that it seems to have A LOT more headroom than the Schiit, so it still sounds good at lower volume. No noise, or background hiss so far, either. Here's hoping these tubes don't "break-in" to a bright nightmare.
 
So, if you're hyper-sensitive like I am, you might want to drop the $45 and experiment. As for tube rolling, are there any compatible ones available on amazon? I couldn't find any, and I don't like ordering from "hole-in-the-wall" (bob's tubes) sites. Can't use eBay (don't ask).

 

[edulov]

If you are using stock tubes just bear that they provide horrible highs and overall mushy sound. Better valves are required, but what you call smoothing still be there because tube based amps are richer in harmonics, especially if they use pentodes like 6j9p. I dealt with sibilance sensitive cans and sibilant tracks and can say that with this amp the worst combinations are "on the edge" w/o damaging the sound or hurting ears.
Talking about tube rolling I ordered mine from eBay - no problems. Amazon's sellers don't have compatible tubes.
 
I am not a seller, but eBay is not so risky, there exist US based top rated sellers. Do not forget that you need a pair of equal tubes. Just look at least here http://www.ebay.com/itm/Mullard-6688-E180F-Vacuum-Tube-Gold-Pins-NOS-NIB-Tested-Strong-More-Available-/172401588219?hash=item2823ef77fb:g:aPMAAOSw9IpX0v9I or http://www.ebay.com/itm/Amperex-PQ-6688-E189F-Vacuum-Tube-NOS-NIB-Tested-Strong-More-Available-/172336256494?hash=item28200a95ee:g:H3kAAOSwFe5X0vOP

 

[sup27606]

Stumbled upon this little amp. I have a question. I saw a new amp has come out Nobsound NS-01E with similar power output as the NS-08E, but with only one tube. https://www.amazon.com/dp/B01I19SBPM/ref=psdc_537344_t2_B014FASL1A?th=1
 
Has anyone compared this one with the NS-08E, and if I am to buy one, which one should I go for, NS-08E or the newer NS-01E?
 
Thanks.

 

[cam94z28]

  If you are using stock tubes just bear that they provide horrible highs and overall mushy sound. Better valves are required, but what you call smoothing still be there because tube based amps are richer in harmonics, especially if they use pentodes like 6j9p. I dealt with sibilance sensitive cans and sibilant tracks and can say that with this amp the worst combinations are "on the edge" w/o damaging the sound or hurting ears.
Talking about tube rolling I ordered mine from eBay - no problems. Amazon's sellers don't have compatible tubes.
 
I am not a seller, but eBay is not so risky, there exist US based top rated sellers. Do not forget that you need a pair of equal tubes. Just look at least here http://www.ebay.com/itm/Mullard-6688-E180F-Vacuum-Tube-Gold-Pins-NOS-NIB-Tested-Strong-More-Available-/172401588219?hash=item2823ef77fb:g:aPMAAOSw9IpX0v9I or http://www.ebay.com/itm/Amperex-PQ-6688-E189F-Vacuum-Tube-NOS-NIB-Tested-Strong-More-Available-/172336256494?hash=item28200a95ee:g:H3kAAOSwFe5X0vOP

I actually found this place near me. They supposedly have 3.5 million tubes in stock, over 2000 different types, in a 7500sq. ft. warehouse. I emailed them, and they have Amperex 6688 JAN, for $7 each. I will be picking up a few on Friday.
 
http://www.thetubecenter.com/contact_thetubecenter.html