Welcome, Guest. Please Login or Register
Decware Audio Forums
03/29/24 at 01:47:02 




Pages: 1
Send Topic Print
Decware MLB with new tubes - has hum (Read 8685 times)
Rivieraranch
Seasoned Member
****




Posts: 2126
Decware MLB with new tubes - has hum
10/18/07 at 23:59:16
 
I ordered some new tubes from Jim McShane, 3 Sovtek 6N1P's for the Decware MLB that I purchased from an ebay auction. I am using a new Sovtek 5Y3GT rectifier that came with the unit.  The tubes I bought from Mcshane arrived today. I connected the MLB to my CD player, plugged in my Sennheiser HD580's and turned on the MLB. I hear more hum than I thought I would. The music sounds beautiful, though.  Is this normal? The sticker under the unit states that it was manufactured in June 2003.
Back to top
 

071019_002.JPG

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
Yoda
Senior Member
***


I ride!

Posts: 64
Re: Decware MLB with new tubes - has hum
Reply #1 - 10/20/07 at 03:38:30
 
Unplug your cdp inputs, plug in Headphones and turn on unit. See if hum level has changed.  If so, then perhaps a ground loop issue.  Location of your mlb or other tube gear for that matter next to other magnetic fields could induce noise as well.  Try it in a different location, on a different circuit, etc.  did you swap the rectifier?

I have a csp2, but my cd is actually a dvd player that when connected to my tv, induces minor hum on the system.  Usually I don't care until I want to listen to headphones which tell all, so I then unplug the video.

Matt
Back to top
 
 

Decware HDT-Alt tuning, Hagtech Cymbals
Hagerman: Chime Gold DAC; Castanet Line Stage; Cornet II, Piccolo, Thorens TD160 w/ Rega Rb300; Oracle Alexandria II TT, Mayware F4 arm w/Soundsmith-Denon dl-103, Yamaha T-1 Tuner
Many fostex experiments....
  IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Decware MLB with new tubes - has hum
Reply #2 - 10/20/07 at 14:32:29
 
I changed the rectifier, and ran different sets of tubes. I changed the interconnects, and have moved the unit to a fairly neutral place on top of a speaker stand. I turned it on without a source connected and it still hums. I plan on making an amp stand using a piece of wood screwed into the bottom the the speaker stand. As it is the unit is resting on the rubber bumpers on the speaker stand's top plate.
Back to top
 

DSC00901.JPG

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Decware MLB with new tubes - has hum
Reply #3 - 11/03/07 at 01:43:52
 
Back to the factory it goes for a good once over. It was packaged and sent out this afternoon. I can hardly wait until its speedy return!

How lonely its MDF stand looks. When the unit returns I will be making a stand for it using that platform and some moulding on the sides, then painting it black.
Back to top
 

071104_001.JPG

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Decware MLB with new tubes - has hum
Reply #4 - 11/10/07 at 15:03:51
 
Steve called on Tuesday, the same day he received the amplifier. I was very surprised; I am not used to such a high level of customer service. He would check it out.

Friday Steve's assistant called; the amp is ready, with some new capacitors, new volume control (N/C)and some updates (very reasonable). I paid over the phone and they shipped the amp that afternoon.

All is well.
Back to top
 
 

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
Rivieraranch
Seasoned Member
****




Posts: 2126
Re: Decware MLB with new tubes - has hum
Reply #5 - 04/11/08 at 03:27:00
 
I began using the amp at my office and for some reason I do not notice any bothersome hum. Go figure.
Back to top
 
 

MINI TORII & ZROCK2 both anniversaried; 'Lil Audio F-15; TECHNICS SL1200MK2 KAB MODDED TT; ONKYO 6 DISC CD; MARANTZ 2226B; SCHIIT MULTIBIT DAC; SENNHEISER HD-580s
55   IP Logged
Pages: 1
Send Topic Print