this seems good right but they say it can have any logo?
1 Like
yes is the Nos Tungsol,good find.The price is crazy good.
It was common for manufacturers to provide other manufacturers with tubes, that would be rebranded.
So youāll see various names on various tubes. For example pretty much every 7F7 tube ever made was made by Sylvania, but they were often rebranded by manufacturers who didnāt make them.
Some manufacturers etched markings into the glass. so you can easily determine who made it where and when. But often you have to go by the construction of the tube.
Some tubes are now rare enough that people will grind off the original markings, and fake them, so if your buying from random sellers, itās worth knowing what to look for.
1 Like
Iāve got a bunch of nice EL84s for sale over on Head-Fi. Theyāre my leftovers from when I had a Quicksilver. Let me know if any of you are interested in any of them, and Iāll give you a better deal. Hereās the link:
4 Likes
the logo should be irrelevant then right?
Iāve seen speculation that there is some quality variation in say an Ei branded Mullard tubes vs the ones Mullard themselves sold for example, but in practice yes all you care about is the construction of the tube ad secondarily where it was made. Not whoās name it was sold under.
Hey guys, question for the Hifiman HE6 owners with Quicksilver amps. Have you ever tried your HE6 on the Quicksilver and how did it sound to you?
The reason i ask is because while i have the Quicksilver for a long time now i never bothered trying the HE6 on it, i thought there was just no way an inefficient set such as the HE6 could sound good on the QS, specially being planars.
I am listening to this pairing right now thinking, wtf is happening here?! LOL, It sounds amazing to my ears, makes no senseā¦
Maybe the Quicksilver is sufficient to my ears because i donāt listen to music super loud so there is enough headroom with lower volumes?
2 Likes
I regularly listen to the amp with the Modhouse Argon T60RP
It can drive Planars really well
5 Likes
Cant wait to join the club! Its gonna take a long time to arrive tho 
I wonder what āfavorite pairingsā could it steal from the pass labs, portable mass kobo, BHC, yamamoto ha02ā¦
Im very excited to roll
EDIT: my mate in tijuana has my QSHA with stock tubes, ill let him have it for like 2 months so he can have some fun with it, then heāll send it to me and ill use stock tubes for like a month to know the amp
I decided to get at least one pair of these, or if possible all of them.
These are vintagetubeservices.com costs, gonna call andrew
12ax7 Matsushita $64
Extremely well made. Warm, sweet tonal balance.
12ax7 Amperex $136+
A bit lighter with a touch more sparkle than telefunken
Matched 6BQ5
Siemens & Halski $108-138
Amperex $84-108+
I think these 2 pairs would be perfect for me
Theres also some interesting tung sol both in 12ax7 and in 6BQ5 but they are low ok stock.
I wonder how much the cost increases for a matched pair?
Still a long time coming to order
3 Likes
Speaking of good pairings, just wanted to throw it out there that the HE1000SE has an absolutely FANTASTIC synergy with the Quicksilver, seriously its addictive.
I highly suggest you guys give it a try if you can.
8 Likes
Has anyone experienced troubles with your QSHA?
Mine was working perfectly fine, suddenly after doing a careful cleaning of the outer parts with a microfiber cloth just removing some dust, it started failing with a loud acute sound on both channels, ive swapped the tubes and the cables and the headphones but the problem remains the same
Man do I have some bad luck, this is the kind of noise similar to white you get when theres too much gain but its present even with the volume all the way down, and it increases as you turn the volume up, rendering the amp unusable
Also, while the rca are disconected theres actually next to no noise at all, but when connected to any dac the noise is as described
Im about to give up on tube amps, just cant seem to get a no issue experience with them 
EDIT: Problem fixed
- Need to turn of my speakers and subwoofers, tv and other stuff
- One of the tubes has a bad contact, I push it a bit forward until it lights up normally
- My voltimeter is showing more voltage than normal from my grounded wall, I disconnected everything I could and its still a bit over 120v
- I wonder If I can get a more comfortable setup that still works without moving everything arround
- Low impedance headphones are getting some annoying hiss, not a deal breaker but I think It has to do with the voltage being over 120, im not sure how to fix that one
Im getting a bit worried that my unit might have had some kind of issue during shipping, one of the 12ax7 needs to be positioned like held a bit toward the back of the back, this is not a big deal I guess but
I expected the quicksilver to be more silent, theres audible hiss on my headphones ranging from 32 to 50 ohm, around 100db/mw sensitivity, above that there is no hiss but I thought it would handle those as well based on what ive read
Im also reluctant to open it up, I dont know that I could fix that, and its a minor issue I can live with, it is a powerful amp with my low impedance cans after all
Is it the tube or the socket?
Hiss is usually a function of some passive component or a tube.
Is it in both channels?
Does it get louder when you turn up the volume?
If you unplug the pre tube can you still hear it?
If you diconect the input can you hear it?
If you short the input can you hear it?
Could also be a bad connection.
But if itās in both channels itās not likely to be a single component, could be ground noise.
I donāt have one, so I canāt comment on whatās ānormalā, but 100db+ sensitivity is going to expose any noise an amp makes.
Assume you canāt. Itās overstated, but tube amps can kill you. I donāt know what the b+ on the quicksilver is, but itās likely north of 250V, and depending on if it has bleeder resistors across the cap and what size they are, that 250V could be there hours after itās turned off
3 Likes
Its the socket, it happens with all my 12ax7, if theyre not in that position they dont light up
Yes both
Yes I can hear it withouth the pre tube
When I disconect the rca input the noise dissapears completely
Im not sure what you mean by shorting the input
I did get a bit less noise with the stock yugoslavia ecc83s than with JJ 12ax7
I think its a ground noise, maybe something moved out of place, it was shipped from very far away
Also for some reason im getting a bit over 120volts on my conditioner measure, which usually never happens
Sure!
Thanks
1 Like
That could cause the noise issue on itās own.
Then itās probably ground noise in the system, and not a problem with the amp. Disconnecting the input doesnāt stop it amplifying, it just basically connects the input to amp ground through the pot. If there is no noise then the issue is the input.
Could be a bad cable (they can hiss believe it or not), or a problem with the source, or itās grounding or lack there of.
Unplug everything except the source and the amp, wire them directly together. try a different cable, try a different source. If you can get source to amp noise free, you add everything else back in piece by piece until you identify the issue.
But if the noise isnāt there with nothing connected to the input, itās the input dragging the noise in.
Note You may not have the issue with SS amps, most SS amp circuits have very good power supply noise rejection, tube amps donāt. Itās why such a large portion of the budget in a tube amp is in the power supply.
Just getting an RCA connector at the input, and connecting the signal to ground with a piece of wire, itās basically passing the amps own ground to itās input. But if you canāt hear it with the RCA disconnected, itās not the amp per se.
Note this is āsafeā on the input, but not on the output, and donāt try it with a balanced input.
Mains power voltage is only specified to +/-5% in the US, and it used to be less than that, the higher end of that can cause issues, but itās usually hum.
2 Likes
Yup, but its not something I should try to fix is it?
Weird, my AC system is fully grounded, and I already tried with 4 pairs of cables, the only thing that reduced the noise was using preamp tubes with less gain or headphones with more impedance
Its not a dealbreaker noise but it bugs me that it shouldnt be there
I do need to test other sources
Most likely so far
Sure thanks
Yes thatās because the less sensitive headphones, or lower gain result in less amplifications of the headphones, so the noise it quieter, to the point itās probably inaudible on some headphones.
Any headphone in the high 90ās sensitivity is a noise magnet, I spent months tracking down the last of the noise in my hybrid amp, and to was completely inaudible on anything but the Utopia and MySphereās, theyāre both stupidly sensitive.
The lower impedance factors in because db/mW is a stupid measurement (db/mV is much more useful), given 2 headphones with the same db/mW rating the one with the lower impedance is more sensitive to voltage fluctuations (i.e. noise), so headphones like the MySphere 3.1 with itās 15Ohm impedance are dramatically more sensitive to noise than the number suggests.
Thatās not what ground noise is, every piece of metal in anything acts as an antenna, so letās say you attach a ground wire to the case at one corner. Weāll call that corner 0V, because itās just a reference, now you measure the voltage at the other corner, it can quite easily not be 0V, the case itself acts as an antenna has some resistance and current will flow from that corner to 0V, it will likely be very small, and probably not audible unless someone is stupid enough to use the case to carry signal ground.
Ground noise if a function of two grounds in a circuit not being the same voltage, and unexpected current flowing resulting in noise, this is a function of how the devices are grounded. Some devices completely float signal ground (I.e. itās not connected to a reference at all), others will ground to power ground at say the input,
Some will ac ground only, some will use resistors or diodes to mask noise, it gets complicated, but as soon as you have 2 sources of ground in a system (DACās often couple USB Ground to Signal ground or Power Ground) you have a potential for noise.
And tracking it down is a pain in the ass, the only way Iāve managed to do it is isolate the components then connect them together one at a time and see when the noise turns up.
For things like hissā you also have to worry about RF interference, sometimes just moving a piece of equipment relative to another can cause hiss.
It can also be really random things like a wall wart on the same circuit, pumping noise back into the power ground that everything shares, or an LED dimmer pumping out RF noise, which is why I said turn EVERYTHING off, and isolate each piece of equipment.
3 Likes
Thanks you very nuch for all the useful info
To keep my answer short ill basically have to test seemingly random stuff over and over, I thought I had tested enough but it might be something as damn random as the yamamoto beside it (it once cause noise to the BHC while turned off because the transformer wasnt screwed tight), maybe the linear power supplys on the wall, idk, somethings got to get
Tube amps sound so damn good but take some real dedication
1 Like
Hello again @Polygonhell
I had actually not been using nor did any tests to my Quicksilver Headphone Amp until now, its kind of very clear whats happening, but I dont know what to do about this, maybe you have some advice.
The Noise is actually not a hiss, the amp is hiss free until you get to extremely loud volumes which is normal.
The noise is clearly identifiable as electric transformer hum.
The testing was done with only the source and the amp connected, cables and everything thoroughly checked.
The more sensitive the headphones are the louder the hum becomes.
The Hum is clearly audible in everything that would be considered āLow impedanceā, that includes all of my Grados and ATHs (I collect these brands) which are all around 32 and 38 ohms, averaging 100db/mw sensitivity.
Any IEMs I tried (sony n3, z5, final a5000, etcā¦) would get a louder hum.
My most sensitive āearbudsā are Yincrow rw4000 with 16ohm and 118db/mw get a very loud and clear hum.
On the Koss KSC75 with 60ohm and 101db/mw the Hum is not audible anymore, its also not audible in anything āharder to driveā than this.
Using the Yincrows for testing. (Though the following applies for any headphones)
The Hum is very loud on the left channel and rather quiet on the right channel.
The Hum does not change at all when moving the volume pot.
The Hum does not change sides when switching sides of the RCA Input or switching the tubesā sides.
The Hum stays the same when disconnecting the input.
So thats basically it. I was already thinking that I needed to send the amp to the Quicksilver but im not sure about it, if you think thats the way to go then it most likely is, I could also try something else, I dont know whats usually done in these scenarios.
I doubt they consider it broken from the description. Iād certainly talk to Mike at quicksilver before sending it back, and get his take.
Itās somewhat ānormalā for SE tube amps in particular to have some detectable hum through very sensitive headphones. It can be worse or better depending on the specific tube (see below).
If the Hum is 60Hz, itās likely caused by RF, either the transformer in the device broadcasting the noise, or something else nearby doing the same. It also depends to a point what is actually picking that noise up, any wire in the amp, including the filaments in the tubes can do it, so can be worse/better depending on the exact mains voltage, and how noisy it is, the specific geometry of the tube.
If the noise is external moving the amp relative to the other device will help, if itās the amps transformer the only real fix is better physical isolation of the mains transformer, which for most hobbyists isnāt practical.
Though It could also be ground noise being pushed into the amp by something else on the circuit, or less likely a ground loop in the amp itself. Thatās basically impossible to diagnose.
And although unusual it can also just be a bad cable FWIW,
The only way to determine if there is an external problem is to disconnect the amp from EVERYTHING, move it somewhere distant from the other devices, and plug it into a different circuit, if the noise isnāt present itās not the amp.
If the noise isnāt present at that point you have to go through the whole move everything else one piece at a time until the noise comes back, and start generating experiments to determine what the cause is and how you might fix it.
If the Hum is 120Hz itās actual noise from the PSU, I actually doubt this, but tube amps usually have little to no way to reject power supply noise (itās one of the reasons they get expensive at the high end), so itās down to the choke (if it has one) and the capacitors in the PSU.
4 Likes