Tubes Glow, but no sound on Ultra 4A

hartwerger · « **on:** 3 Apr 2006, 02:13 pm »

Does anyone know or recommend a tube audio repair shop in the Baltimore, Maryland area? My Ultra 4A has stopped working. It powers up and the tubes glow, but no sound. I thought I could hear a very very faint sound last night with the volume knob cranked all the way up, but this morning I don't think I could hear anything. I bought this unit used so I don't know exactly how old it is, but I'm guessing its at least a few years old. I also know that it had some upgraded capacitors and resistors installed about 18 months ago by Anitgue Radio Service in California, but since I live here on the east coast, that seems like a long way to ship this unit for repair. There must be some other reputable repair shops out here. I thank everyone in advance for any help or recommendations. Its too quiet and sad here in my house.

nodiak · « **Reply #1 on:** 4 Apr 2006, 06:14 pm »

hartwerger, sometimes a tube needs reset gently in the socket. Gently wriggle it with some easy downward pressure and see if it helps. Have you tried other tubes ? Also check your plugs and cables. I tried a dif pre recently and had accidently pulled the dac plug out just enough to disconnect it, even tho it was still resting in position. That was a good one!
I am interested in that model or the Line 2. May buy the SE model of either. Will look for used as well. (Yes I would be interested in yours but not trying to scavenge it from you in your time of need. But yes let me know if...).
I hope you at least call Antique Radio Service, they should be helpful. Also Mapletree, they are ~ near you, and their site says shipping is ~ $25 to usa, plus he would be the best to repair it.
So how do you like it? I find I may be a large tube (like the octals in yours) person rather than small tubes. I just got an upgraded MiniMax-uses 12au7 and 6x4 tubes. It's great but I think I need the fullness of octals. I will find out.
Don

dpump · « **Reply #2 on:** 11 Apr 2006, 02:08 am »

Which power supply are you using with your preamp? If you are using the PS1T or the PS2, you have a 6x5 rectifier tube for the high voltage. There is a separate transformer for the 12volt heater supply. The tubes will glow if they are getting the 12volts, but there will be no sound if the rectifier tube is bad. The fix could be a new 6X5 rectifier tube.
I have the Line 2M with the PS1T power supply. I actually have the Line 2M that is reviewed on the Mapletree site. With the Dr Lloyd's help, I moved everything to the larger chassis and configured it with 6 inputs and 2 outputs. I upgraded to Auricaps and Black Beautys. Volume control is an Alps and the balance control is an Alps Black Beauty. Selector switch is an Electroswitch.
I recently, again with the Dr's help, started using a Bendix 5852 rectifier tube in the PS1T. This was a large improvement over the 6X5. If you have a PS1T, you only have to change one resistor to use the 5852. I would highly recommend this change.
If you have a PS2 power supply, you cannot use the Bendix 5852. Repeat, you cannot use the 5852 in a PS2 power supply. It is a different design from the PS1T.
The bottom line is that the Line 2M is an amazing preamp. You only need three tubes-two 12sn7 and one 6X5-to have a fantastically musical sound. All the detail is there and the sound is so pleasing. I had a $3000 Coda preamp when I bought the Line 2M just to play around with. I sold the Coda shortly after and I've never regreted it.

Dave G · « **Reply #3 on:** 2 May 2006, 01:28 pm »

hartwerger,

I gather from your comments in another thread (ricky588's thread on the Ultra 4 SE), that you must have got your Ultra 4 back up and running. What did the problem turn out to be?

Dave

hartwerger · « **Reply #4 on:** 2 May 2006, 07:07 pm »

Yes, the Ultra is working again. Thanks for asking and the help and suggestions from everyone. I guess I should have posted this, but I just got it back from Dr. Peppard a couple of days ago. Turned out to be a loose resistor. A simple fix. I have no idea how it came loose as I do not move my equipment around. The oddest part of the story is that the shipment took 16 days to get to Dr. Peppard in Canada and only 5 days for its return to Baltimore. Can't figure out that discrepancy. Anyway, I'm not only glad to have it back and nice to know it was nothing serious (which also should relax our fellow Ultra owners out there).