[hood177]

MAZDA by Telefunken 12AX7 + Psvane CV181-TII ‘grey bottle’ on the photo.

ICON AUDIO HP8 MK2 Russian Bear Edition

 

[hood177]

Thread is dead.
No more enthusiasts for Icon HP8?

 

[Nik74]

People are busy enjoying it most probably

 

[Blueshound24]

Well the HP8 just works and is one fine amp. Nothing I have had has bettered it and I'm very happy with mine. I'll bet there are many content silent owners out there.

 

[hood177]

Well the HP8 just works and is one fine amp. Nothing I have had has bettered it and I'm very happy with mine. I'll bet there are many content silent owners out there.

Where are the updates, modifications and improvements?
For several years, I modified a couple of my Icons three times.
Electrolytic and oil capacitors are tired of the heat and this is a reason for new modifications.

 

[Blueshound24]

I'm not much of a modder. Usually just happy with whatever I choose to keep in my system. If it is not to my liking i will just buy something else rather than try to change it.

 

[Nik74]

I'm not much of a modder. Usually just happy with whatever I choose to keep in my system. If it is not to my liking i will just buy something else rather than try to change it.

Very much the same here. If you haven’t had the Jensen capacitor upgrade though - offered by Icon Audio but easily undertaken by your local audio engineer- , that is a strongly recommended step to getting the most of the HP8.

 

[RobertSM]

I use my HP8 MK2 almost daily. I've found alot of enjoyment with upgraded capacitors and NOS tubes. Specifically, I find that the ECC83/12AX7 input tube of the HP8 MK2 has a big impact on overall sound. Presently, I rotate between a Siemens NOS tube and a Mazda France tube. To me the Siemens offers a fuller bandwidth spectrum and a little more overall gain. The Mazda, a really pretty top end with great air and sparkle.

 

[-Darkstar-]

Nothing really to update on. I'm enjoying mine with my Fostex TH900 Mk2's. Just a solid all around amp and I have no real desire to change it out for something else.

 

[Jay Smith]

Last month I had consistent static noise in my HP8 mk2, and recently I figure it out the noise came from my new D-link home plugs, but my Beyer A2 amp does not have that static noise, I guess tube may be more sensitive to those high frequency noise. Now, I am enjoying HP8 with T1.2 again, it is a good amp.

 

[hood177]

Nothing really to update on.

Probably you have not yet heard the real sound of the Icon......
Like any tube amps, Icon HP8 has great potential for improvement.

 

[MLGrado]

Mine is dead. Enjoyed for over 2 years. No mods but lots of tube rolling. I own over 100 vintage 6SN7 types and several hundred vintage 12AX7 types from every factory you can imagine. Telefunken to Mullard, all the Phillips factories, all the varied French tubes and even several 1948 NOS RCA 12AX7 that are some of the very first made period. Even have General Electric/Ken Rad factory engineering samples that are also late 40s!!


Anyway I killed a socket most likely via tube rolling. I started getting some noise I attributed to the tubes, and on the very next roll something ‘gave’ in the 12AX7 socket and now there is a major hum.

Took bottom access panel off, and all looks correct, but moving the tube in the ‘AX7 socket causes just a bit of movement in the parts array below the socket making a ‘spring-like’ sound that wasn’t there before. It looks like one of the socket Leads moves too much. More give than normal.

So I suspect all the sudden noise problems was never a tube, and I made it worse with one final tube roll that damaged the socket internals that connect tube pin to leads below.


Icon Audio referred me to the authorized dealer in US for repair. Of course Music Direct.

Music Direct won’t service it, though since I did not purchase it from them. Both Icon and MD suggested I find a local repairman. I have yet to have any luck after several promising looking options have not returned my calls yet.

MD DID give me the phone number to the repair center in Chicago that does all of their repair and upgrade work on Icon Amps. I haven’t called them yet.

My other option is of course do it myself. I have all the necessary tools including a pro variable solder station and I have what I would call average skill. But that scares me a bit.

Anyway I am doing the cap upgrade too but am confused by the values as well being quoted by Icon for the coupling caps. The value on the Solen MKP caps is specifically 0.33uF 630v. That’s not what folks are being told about the Jensen upgrade, though. The tech at MD did tell me the stock caps in the Hp8 MKII do NOT measure at their rated specs. Maybe that has something to do with it.


Finally, does anyone have a recommendation for a tech? Before I send to Chicago where it could sit for quite awhile low on priority list, or before I fire up my own equipment??

Thanks!

 

[Blueshound24]

Mine is dead. Enjoyed for over 2 years. No mods but lots of tube rolling. I own over 100 vintage 6SN7 types and several hundred vintage 12AX7 types from every factory you can imagine. Telefunken to Mullard, all the Phillips factories, all the varied French tubes and even several 1948 NOS RCA 12AX7 that are some of the very first made period. Even have General Electric/Ken Rad factory engineering samples that are also late 40s!!


Anyway I killed a socket most likely via tube rolling. I started getting some noise I attributed to the tubes, and on the very next roll something ‘gave’ in the 12AX7 socket and now there is a major hum.

Took bottom access panel off, and all looks correct, but moving the tube in the ‘AX7 socket causes just a bit of movement in the parts array below the socket making a ‘spring-like’ sound that wasn’t there before. It looks like one of the socket Leads moves too much. More give than normal.

So I suspect all the sudden noise problems was never a tube, and I made it worse with one final tube roll that damaged the socket internals that connect tube pin to leads below.


Icon Audio referred me to the authorized dealer in US for repair. Of course Music Direct.

Music Direct won’t service it, though since I did not purchase it from them. Both Icon and MD suggested I find a local repairman. I have yet to have any luck after several promising looking options have not returned my calls yet.

MD DID give me the phone number to the repair center in Chicago that does all of their repair and upgrade work on Icon Amps. I haven’t called them yet.

My other option is of course do it myself. I have all the necessary tools including a pro variable solder station and I have what I would call average skill. But that scares me a bit.

Anyway I am doing the cap upgrade too but am confused by the values as well being quoted by Icon for the coupling caps. The value on the Solen MKP caps is specifically 0.33uF 630v. That’s not what folks are being told about the Jensen upgrade, though. The tech at MD did tell me the stock caps in the Hp8 MKII do NOT measure at their rated specs. Maybe that has something to do with it.


Finally, does anyone have a recommendation for a tech? Before I send to Chicago where it could sit for quite awhile low on priority list, or before I fire up my own equipment??

Thanks!

I would like to know too for some needed repairs.

 

[hood177]

Finally, does anyone have a recommendation for a tech?

I highly recommend leaving the capacity of capacitors 0.33uF 630v. It is also necessary to double the capacity of all cathode capacitors. And the sound of the Icon will be at the highest level.
And use only ceramic sockets. Teflon sockets are very soft and quickly deformed.

 

[MLGrado]

Ok, got the correct capacitors soldered in. Stuck with the Mundorf Mcap supreme silver oil. Presently, burning in a pair of the new Sophia electric 6sn7 blue glass tubes and a 12ax7 also from Sophia.

I'm about 25 hours into the caps & tubes burn-in. Very much impressed with what I hear so far. Great detail and air to the sound signature. I know the term gets used alot, but I find this Icon Audio HP amp to be very musical. Also, I'm impressed with how black the amp is. Totally silent. Like, I hear zero distortion. In regards to power, this solidly built, hefty little amp has plenty of power. No issues at all driving my Sennheiser HD-6XX headphones with authority. Also, I did read a few prior comments regarding transformer noise/hum. I'm thankful that my unit is totally quite.

More to come as I get used to the amp and post caps and tubes burn-in. But this is really turning out to be a great amp.

Hi,

How goes your amp these days??? I actually ordered a brand new one and I just got it today from MD Chicago. I still have my 'wounded' one on the bench and I am slowly working through the process of changing the 9 pin ceramic socket.

My real question again is about the coupling caps. I am not going to touch the new amp; it sounded really poor at first, but after several hours is settling in nicely. Tube rolling makes a major change. I am using what I think are about the best 6SN7 types... they are actually 6F8G Tung Sol with adapters. Just makes an AMAZING difference over the stock tubes. Right now have an RCA 5751 black plate triple mica in the pre spot.. nice, nice tube. Not my best, but I have kind of a fondness for it. Anyway, I digresss..


I KNOW the difference tube rolling makes. I am really curious how much difference the cap upgrade makes. I bought the Jensen .1 630v as many of you say Icon recommended, but I am thinking of getting a pair of the .33uf as well, since that is clearly the value of the stock caps. Anyone have a summary of the reason Icon is giving for the value change? My research says that the biggest difference will be in the bass output, as in LESS bass going to a smaller value cap.

Just curious, and wanting to kind of stir up some talk about this great amp that seems like a lot of people just enjoy and leave it at that! Rarely do you find these second hand. People must just be holding onto them and enjoying. In any case, I hope they have at least tried tube rolling. And as for myself, I am afraid I am about to jump down another rabbit hole with caps... ph my.