[dgcrane]

I on the other hand had a really hard time with the MKII. Unfortunately I sent it back... twice. Once to get the switch put in by Garry and then once after when I was still not happy with the amount of hum I was getting running both stock and NOS tubes. I could not seem to get a combo of tubes which made me happy even with my HD650's which are 250 ohm I believe. Grado's were out of the question......
 
Garry agreed to accept the return (I paid return shipping costs twice plus the paypal charges for him to return the money to me.....)
 
I ended up buying a mkI from Big Bill since and could not be happier with it. There is no hum and sounds wonderful IMO.
 
Darren
dgcrane

 

[micmacmo]

Quote:

 
I ended up buying a mkI from Big Bill since and could not be happier with it. There is no hum and sounds wonderful IMO.
 
Darren
dgcrane

I've avoided the temptation to move from the Mk1 to the Mk2 myself. How do you feel the two compared (hum aside)? And what phones did you pair them with?  
 
(BTW, nice avatar!)  
 

 

[dgcrane]

I have a relatively modest speaker setup, so my intention when I ordered the mkII was for it to be a headphone amp. I ran the MKII with HF-2's, HD650s and Darth Beyers 80 ohms. I could not get past the hum with any of those headphones. I play at relatively low volume and during quieter passages, the hum was truly downright annoying to me. Through my mission bookshelves, the sound was great and no hum could be heard. I find the MKII more visually appealing and love the fact that the speaker jack is in the front. Other then those two things, for me the MKI wins hands down.

Darren

 

[BmWr75]

When my MKII came, one channel was wired incorrectly at the transformer (IIRC).  Gary told me what to check and sure enough the problem was a he stated it to be.  All I had to do was disconnect 2 plug-in wires and reverse them.  Other than that, it has been a fine amp at an entry level price.
 
It does hum more than I like with LCD-2s and I would be unhappy with it if that were the only amp/hp combo I owned.

 

[dgcrane]

I simply wanted something entry levelish for my nightstand that would be a good pairing with my headphones which I love The MK1 seems to be a better solution for my needs. I also have a millet max in my office which is also pretty inexpensive and makes my grados absolutely shine.
 
Darren

 

[micmacmo]

I'm pretty happy with my MK1 as well. I'm using it to drive k701 and, while I've tried other amps including solid state, I really like this combination. It can be a bit bass-light, but the sense of space and airiness and its deft touch with vocals keep me coming back.

 

[eclein]

My first one was the MK1 which I sold to Big Bill on here and then I got the MK2 and initially had hum isues with speakers regardless of the tube or combination of tubes, after time it lessened and now it is totally and completely gone. I use this with speakers and find it excellent. The MK1 sounded great too but the MK2 just seems to have more balls, maybe its that extra .5 watt!!!!!
 
I have Mullard reissued EL34's in back and
real Mullard pre-amp tubes (6SK7GTs) and I have no desire at all to switch anything up right now and doubt that will change any time soon....I love mine!!!!

 

[micmacmo]

Quote:

...I got the MK2 and initially had hum isues with speakers regardless of the tube or combination of tubes, after time it lessened and now it is totally and completely gone...

eclien, any idea why the hum disappeared? 

 
Anyone else have a similar experience? 
 

 

[dgcrane]

My MKII system burned in for well over 100 hours. I assumed if my hum wasn't gone by then, it was never going away.....
 
Darren

 

[BmWr75]

Quote:

eclien, any idea why the hum disappeared? 

 
Anyone else have a similar experience? 
 

These type of driver tubes sometimes get quieter over time.  Have no idea why......
 

 

[eclein]

Not sure why but I can say that when I swapped out tubes the first time it was the pre-amp tubes andpower tubes I changed-still had the hum. Put the stock pre-amp tubes back in and hum went away 95%-so stock in front and swapped out the back ones and hum went away. Then as I was convinced it was gone or at least low enough I could tolerate it I talked to Skylab who had gotten these pre-amp Mullards (very hard to find) so I put thos in and even less hun, now its pretty much zero!!!!
I ran mine in a bit differently though, I would turn it on and play music for maybe an hour or 2 each day and then turn it off. I did that for like a week and a half and the hum decreased and decreased. I would talk to Gary if I was you, he's the designer and very, very helpful...just tell him whats up and he'll work to resolve it...seriously.

 

[Rockyhill]

Things are looking up! Red can RCA 5693 have greatly improved the hum. No idea how many hours are on them prior to arrival here but I'll run them as much as I can and will note any changes. I'm also working on getting the Mullard 6SK7GT's.
 
I'm now a much happier Maine Man

 

[eclein]

Rockyhill....Gary is very easy to deal with and will do anything he can to help you out so don't be put off about trying to contact him.
 
When/If you find those tubes please tell us where you got them, I have no clue where to look...LOL

 

[Rockyhill]

I agree Garry is easy to work with. He swapped amps without question. (After I paid $52 to ship original back)
 
However the symptoms are the same. His reference to the "tiny hum" within centimeters is not accurate. The fact that this is a very sensitive design that allows quiet performance with some tubes and very loud hum with others is frustrating, IMO. The amp with stock tubes should not have audible hum when standing 8 feet away. Rolling tubes to remove/reduce hum is, to me, like being asked by a car manufacturer to switch tires to resolve a squealing issue on a car with a poor suspension design.
 
Now that I'm on my 5th set of driver tubes I'm somewhat more satisfied. 
 
I can't imagine that these reports of hum (here and elsewhere) are having a positive effect on his sales. I would think he'd want to correct the cause of the sensitivity so the various forums would be talking about how wonderful this amp is (like the original once "snipped").
 
 
Just my 2 cents
 
 

 

[Greeni]

I found that the hum with my unit was considerably reduced with use. It was still there with efficient phones but much more acceptable. Also the really funny thing is the operating temperature of the amp was reduced with run-in. Nice. 
 
I would like to hear others' experience with the impedence switch mod, did that reduced the hum and the gain level at the same time ?