Project Headphone amp build thread.

[PinkFloyd]

PS: now that I am feeling a LOT better I'll try a few caps in the Sunrise and see what my "ears" think are the best (if any) type / value of film cap... as I say, it's a great amp to learn on as there are only a few caps on board.

Mike.

[joethearachnid]

Mike,

I can't speak for Frans, but I feel that his statement may have been referring to the integrity of the electronic circuit rather than the sound quality, i.e. you can bypass all the caps but it should still work as an amplifier of some kind and shouldn't explode in your face or burn your voice coils.

Doesn't make your comments any less valid generally, though.

-JoetheArachnid

[Deleted]

Yes ... you won't blow anything up bypassing caps.

Funny thing about bypassing and it's sonic abilities.
It's highly subjective.

The effect of proper bypassing is quite measurable in certain cases (very fast amplifiers and switching circuitery, especially the higher speed things)
The sunrise is comparably a very slow amp (dependant on used tube between 10kHz (-3dB) and about 160kHz (-3dB) and thus decoupling in the MHz range (1nF and smaller) is not really needed nor technically beneficial.
Proper (technical) decoupling is already present in this amp and technically adding more caps directly below the large PS cap (which is NOT the best place to decouple technically) will have no technical effects, at least not measurable.
For subjectively perceived differences Mike is on the top of the game and it can't hurt to follow him.
placing extra caps will most certainly result in a change of SQ, depending on the used cap.
It just cannot be proven in a court of law or by any test equipment nor in any blind test as these are simply not revealing enough.
At least that is the theory behind subjective listening tests.

I too have over 25 years of experience in audio (designing, developing, repairing, tweaking and over 10 years of experience with professional PCB design (and now about decoupling) AND access to good ears (my own), experience and lots of parts and vewwwwy expensive test-equipment and labs as well.

I too have used my ears (in a subjective way) but after some years of only subjective tests, and realising I could easily fool myself when I (thought) I knew what was changed, wanted to take out the 'knowing part' and devised different test methods that are less... ermm... subjective.

Needless to say (non-subjectivst techs will understand) I have drawn other conclusions based on HEARING alone.
Ofcourse that is only my opinion.... not being a subjectivist. ;D
I know I am wrong ofcourse but can't help being somewhat thick about it.
Probably related to my posture as well.. ;D

the above is only posted in my defence and not really from a subjective viewpoint which may be one of my weaker points.

Yes... I have little to do in my hotel room, hence the rant. ;D

[PinkFloyd]

Not even worth a response Frans. You are hooked on measurements, I am hooked on using my ears... ces't la vie

[PinkFloyd]

BTW... Hotel room? Are you on holiday? Last time I was in "an" Hotel they threw me out because I didn't measure up correctly to their test equipment.... (I burnt a large hole in the duvet / bed with a cig)....

They did stress that they were ejecting me for "smoking in the room" (as it was prohibited) and didn't want to listen to my argument that I wasn't smoking... I was trying to set the Hotel on fire

Apparantly "attempted Arson" is cool but smoking is STRICTLY prohibited

True account by the way.

Night night.

[Deleted]

Work related.... the hotel in Germany.
Going home again tomorrow.

And re the comment above... I use HEARING but with different test methods.
Blind AB or differential, both using ears and real music.
It´s leading, always has been.

I only use test equipment to verify what I am hearing is indeed correct.
Fortunately for me there is always a direct relation between the listening tests and measurements when differences are perceived.
Not so when tested subjectively which is why I use my methods.

a matter of preference and hardly debate-able, certainly not in this thread.

[davefo]

Sept 11, 2011 13:47:29 GMT @cjarchez said:

I held back on this one for the reason of external interferences as experienced with the G2. When I first got it things weren't too bad but after moving both home and business my new environments seem to be very noisy for this amp.

If a MKII did happen, within a case, ie kit form with case provided then I may be interested.

Christians point about pre-mounting any SMDs X2

I didn't have too much of a problem mounting the led.
Used a magnifying glass and some tweezers. tinned the pcb connections then held the led in place and added a bit of heat from the soldering iron. when one connection is done its then easier to do the rest.

[Deleted]

yep, that's correct

having recently delved into SMD soldering this is no longer an issue.

My comment on interference, in my circumstsances, however, still stands.

Oh, and welcome!

[Deleted]

Mind you Chris, on the one that Mike put together for me, the issues that I was getting completely vanished.

If I'm honest, there is now no noise or interference. In fact, it's remarkably good for an open design and noise levels have been completely squashed to virtually nothing.

It is a lovely little amp. Very warm and powerful but I enjoy music through it a great deal. It's a little cracker of an amp really.

However, Mine has a good bit of power behind it, valve shield, extra heat sinking and earthed vol pot plus some capacitor changes and it's fantastic now and runs cool as a cucumber.

They are small changes but have made a big difference for me, but then, Mike has always been able to shut noise out of amps for me amazingly successfully. When I first had the V2, I had a bit of noise coming through. (Tiny, but there) Mike nailed it completely and it's now absolutely silent. He tells me that he uses magic dust. ;-)

[davefo]

Nov 13, 2011 15:42:55 GMT @cjarchez said:

yep, that's correct

having recently delved into SMD soldering this is no longer an issue.

My comment on interference, in my circumstsances, however, still stands.

Oh, and welcome!

cheers

I've not been into audio electronics long, but am very interested in what everyone is discussing.

I have noticed the hum on my amp, but only when music is paused and pot turned to 2 oclock. I listen at about 9.30 so probably not a problem, but i did the earth mod anyway and it has certainly solved it. Now want to get rid of the remaining underlining hum and hiss if i can. I'll probably swap for 3300uF caps and try the bypass wima caps. I'll look at adding a valve shield as well.

I enjoy messing around so long as it doesn't break anything.

Dave

[Deleted]

I have noticed the hum on my amp, but only when music is paused and pot turned to 2 oclock. I listen at about 9.30 so probably not a problem, but i did the earth mod anyway and it has certainly solved it. Now want to get rid of the remaining underlining hum and hiss if i can.

The exact same thing that I was getting. Have you also found that the volume pot reacts to touch and more noise is introduced? The valve shield and extra heat sinks also acted as a shield, buty I suspect that some of my noise was coming through the mains as well. The vol pot is earthed and now, I'm really chuffed with it.

Jeremy couldn't duplicate what I was getting on his but I always felt that it was a matter of time before someone else got the same result. Anyway, it's toatally fixable which is the main thing.

[davefo]

Yes i was getting more hum when i touched the vol. I also noticed it reduced when i touched the metai surround on the headphone plug. So i did ghe earth mod. Just wondering how to eliminate the remainder of the bum and hiss. Is yours completely silent now?

I think it is mains hum it sound exactly like it.

Not sure what the hiss is though.

[Deleted]

Is yours completely silent now?

Yes. Mine has completely gone. I was getting hum at about 2 o clock plus hiss. The vol pot was just a simple earth tag.

Not sure whether the hiss was valve related but the hum was very annoying and because I learned the pitch, I started to hear it at low volume as well.

IMO, it was the Sunrise's biggest problem but I'm not sure others were getting it. Jeremy couldn't duplicate it either. I felt that it was a matter of time before it appeared somewhere else.

Mike may be able to suggest ideas to nobble it.

[davefo]

Ian

If you have nothing connected to the interconnect cable can you here the hum again but even louder. I noticed this when i unpluged the cable from my ipod 3.5mm jack. I dont know if this is normal. I'm wondering whether a ferrite around the power supply would help.

Mike

If you see this I'd appreciateany suggestions you can give.
Ill order some 3300uF and 3.3uF caps and a valve shield

Dave

[Garage1217]

Hey Ian, I am sure it was there but just could not replicate it. Also to note, you were comparing a prototype amp to a production amp at that time. There were several differences between them. I was able to duplicate a volpot noise by touching the actual metal housing of the volpot itself but it went away totally when I did not touch the volpot and or if the amp was plugged into a source. It could also be the difference between our mains voltages as well. I am grounding g1217 built amps now just as a precaution. Hope you guys are enjoying the amps

[Deleted]

Enjoying it? It's a great little amp!! I love the Sunrise with the Beyer DT990. Really fruity sound.

When I was getting noises, it was with nothing connected as well as with everything plugged in. There was also a kind of 'focus' to the sound at 2 o clock. If I went a bit further, the sound stayed but became less intense.

However, Jeremy is right - mine was a prototype and some changes have been made since.

[PinkFloyd]

Really fruity sound

I would say tinned peaches with a drizzle of carnation milk.

[Deleted]

Nov 15, 2011 9:07:59 GMT PinkFloyd said:

Really fruity sound

I would say tinned peaches with a drizzle of carnation milk.

;D

Tubes are tasty......

[PinkFloyd]

Hope you guys are enjoying the amps

Will soon be enjoying it again Jeremy... have been "offline" with a pretty nasty chest infection but am starting to listen to the music again so must be on the mend

The Sunrise is a fantastic amp.

[davefo]

I'm loving the amp. Only problem now is that i keep wondering how much better it might be with better headphones. I'm currently using it with my modded superlux hd681s and audio technics ath m35s

[Deleted]

The superlux is a really good headphone; especially when the filter is on. Nothing wrong with that.

[Garage1217]

Here is an easy, hidden fix for anyone that has experienced what Ian has with noise when the volume pot is at 2o'clock. This seems to be primarily with euro customers running 220V. I was finally able to duplicate it running a 220V converter and could hear it with very sensitive headphones, but could not hear it with less sensitive cans. This little mod per Mikes suggestion made it totally disappear.

[davefo]

excellent idea gents. I'll be removing the wire and doing this instead. Much neater than having a wire connecting to the cap leg. Now I might try and sort out a tidy 3.5mm input sock.

I've sorted out my hum problem at 2 o'clock. I beleive it was airborn pick up from the interconnect leads. I though there were good because they were gold plated. Turns out they must have been poorly shielded. I changed them for some hiigh quality digital shielded ofc cables and theres now no hum at all, Cables are like these:
www.amazon.co.uk/Metre-3-5mm-Phono-Cable-Mountain/dp/B000NHOMSQ/ref=sr_1_2?ie=UTF8&qid=1322337502&sr=8-2

The ones I have are home theater interconencts so I have a phono to 3.5mm adapter on one end into a 3.5mm to 3.5mm adapter into my fiio L3 ipod dock lead. A bit messy but I didn't want to cut them up so until one of these arrives it'll have to do.

[Deleted]

Excellent, Jeremy. That's basically what Mike did to mine apart from all the other things with heatsinks and shielded valve.

It is quiet as a mouse now!! I hope that my comments haven't hurt sales of these amps.

Anyone taking my early comments as a criticism, please don't. It's a minor issue that is fixed easily.

This amp is fantastic sounding and is a top notch buy for anyone who enjoys the valve experience. It has top notch experience behind its design and the sound is amazing at that price level.

I have been testing an amp that also uses a valve for the past month or so that also has an amazing sound, but we're talking more like Graham $lee Solo prices rather than what Jeremy is offering here.

The instructions are amazingly clearly written; even I understood it and I haven't soldered for 20 years!!

The Sunrise is a lovely amp and I tend to be quite obsessive about minutia.

In a way, Jeremy, in hindsight, I should have spoken to you backstage about it and I regret talking openly here in case it did any sales damage.

I'm doing the same for another amp, but this is all pre-release and getting sorted before it appears - this is more expensive and I still found minor issues. I'm pretty one tracked with these things.

Please believe me when I say, this is a beautiful sounding amp and noise issues have been resolved completely.

[Garage1217]

No worries Ian, It is a problem that was difficult to duplicate here on our mains but it was an issue nontheless that needed to be addressed. I appreciate you bringing it to our attention!