Jon Anderson Posted March 1, 2004 Share Posted March 1, 2004 Being new to tubes I am curious If I should expect ANY hum from an at rest tube amp through my horns. Recent 233 rebuilt by Ryan Inman is dead silent. Brand new Kailin / Jolida EL34 based integrated amp off ebay generates a discernable hum. I've been told by seller to reseat the tubes, let the tubes burn in, try a different source, stand on my head. Amp still hums. I tried the amp on a set of Large Advents. Advents are very inefficient so the hum is not noticable. But on my Cornwalls or Klipschorns it sounds like crap compared to the Scott. Returning the amp to the seller for an exchange is course I expect to pursue. However I'd apprecaite some input from those with many more years of tube experience. Are my expectations out of line? Thanks.. Quote Link to comment Share on other sites More sharing options...
garymd Posted March 1, 2004 Share Posted March 1, 2004 You should return it. A new tube amp should certainly be at least as quiet as a 40+ year old tube amp. I've only been into tubes for less than a year but this seems to make sense to me. Something is wrong. Quote Link to comment Share on other sites More sharing options...
Daddy Dee Posted March 1, 2004 Share Posted March 1, 2004 hope you have a satisfactory outcome returning the Jolida Quote Link to comment Share on other sites More sharing options...
D-MAN Posted March 1, 2004 Share Posted March 1, 2004 Yes, I can hear some very slight hum or hiss (more like a hiss) from my midrange horns at idle. I have to be within inches of them to hear it practically with my ear up to the horn. This is with late model 6550 monoblocks of reasonable quality using the best interconnects that I have. My SS McIntosh is dead quiet even at that close range same interconnects. DM Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 1, 2004 Share Posted March 1, 2004 Yup should be pretty much dead silent. One thing I would try before sending them back and raising heck with the sellers. Use a cheater plug to lift there 3 wire AC cords from ground in many homes these can raise heck and cause hum especially if some other component in your system is grounded. Just give it a try you may or may not be surpised. Craig Quote Link to comment Share on other sites More sharing options...
mikebse2a3 Posted March 1, 2004 Share Posted March 1, 2004 ---------------- On 3/1/2004 8:56:08 PM Jon Anderson wrote: Being new to tubes I am curious If I should expect ANY hum from an at rest tube amp through my horns. Recent 233 rebuilt by Ryan Inman is dead silent. Brand new Kailin / Jolida EL34 based integrated amp off ebay generates a discernable hum. I've been told by seller to reseat the tubes, let the tubes burn in, try a different source, stand on my head. Amp still hums. I tried the amp on a set of Large Advents. Advents are very inefficient so the hum is not noticable. But on my Cornwalls or Klipschorns it sounds like crap compared to the Scott. Returning the amp to the seller for an exchange is course I expect to pursue. However I'd apprecaite some input from those with many more years of tube experience. Are my expectations out of line? Thanks.. ---------------- I've owned a pair Dynaco MKIV, Heathkit UA-1 , AES SE-1 {2A3} amplifiers and except for a bad ground connection on one of the Dynaco MKIV all where silent on my KHorns. I've also had several Dynaco ST70, Knight , McIntosh 225 , and a Marantz 8B that I have repaired for friends hooked to my KHorns and all where very quit on the KHorns. If the amps are designed right and operating properly then a tube amp should work very well with the KHorns. Does your amp Hum through both channels? Is the Hum loud enough to be heard at your listening seat? At most the hum I have heard from the above amps would require you to be right at the Khorn to hear them at all. Sorry I've got no personel experience with the amp in question but hopefully someone familiar with your model amp will reply and tell you if this design has a loud hum level. mikeb Quote Link to comment Share on other sites More sharing options...
analogman Posted March 1, 2004 Share Posted March 1, 2004 The noise floor on tube equipment is not a universal standard.Is the "hum" present during blank grooves or between tracks?(when a source signal is present,but no "content"). To assume the amp is defective is presumptive. How does it perform otherwise? How can people that are not in your listening room give you meaningful input? Tube amps ALL have SOME "HUM" , if you can hear it or if it bothers you,that's another issue. Hope you resolve the problem!!! Analogman Quote Link to comment Share on other sites More sharing options...
NOSValves Posted March 1, 2004 Share Posted March 1, 2004 No experience with the Cailin but the Jolida amps I have heard were not hummers. What leads me to believe its the ground loop problem is that both the modern amps that have 3 wires are humming and the vintage which unless Ryan replaced the power cord is a 2 wire with no hum. Craig Quote Link to comment Share on other sites More sharing options...
Jon Anderson Posted March 1, 2004 Author Share Posted March 1, 2004 Hum is constant and very noticable from 10 feet away through both speakers. Does not seem to be affected by volume control. The ground cheater plug made no difference. Hum is present without an input sources RCA plugs connected to the amp. The amp has both an AC and a DC power switch. The hum goes away when AC switch is turned off. This turns off the three small fans. Seller has been very responsive but the amp is heavy and will cost $ to ship back. But that's where this ebay transaction is headed. All I wanted to do was compare a new tube design to the Scott and got burned. As always, thanks for your input. Quote Link to comment Share on other sites More sharing options...
analogman Posted March 1, 2004 Share Posted March 1, 2004 Craig and Ryan are two folks that I admire because their insight is MEANINGFUL and OBJECTIVE based on UNDERSTANDING and not superficial anecdotal BULL SH!T.They don't say stupid things that fuel the fears and apprehensions of the uncertain. That, my friends, is the definition of a leader! Enjoying the Smart Guys!!! Analogman (The Troll) Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted March 1, 2004 Share Posted March 1, 2004 Man, your decription sounds like a highly modified Jolida.... actually, like no Jolida I have heard of. This amp has 3 (!) fans??? I dont even think the Jolida EL-34 amps NEED one fan, let alone three. This amp is definitely a trip on the left side of stock, and from the sound of it, not exactly a trip I would take. Yes, purely conjecture, but your description of the mods is way out there. I am imagining what anyone would be thinking to do this. Any pics of this beast? Have you substituted any other tubes in the driver stage etc or elsewhere? HAve you tried plugging it in a different outlet? Are you in a power filter or directly to the wall? kh Quote Link to comment Share on other sites More sharing options...
garymd Posted March 1, 2004 Share Posted March 1, 2004 ---------------- On 3/1/2004 10:32:58 PM analogman wrote: Craig and Ryan are two folks that I admire because their insight is MEANINGFUL and OBJECTIVE based on UNDERSTANDING and not superficial anecdotal BULL SH!T.They don't say stupid things that fuel the fears and apprehensions of the uncertain. That, my friends, is the definition of a leader! Enjoying the Smart Guys!!! Analogman (The Troll) ---------------- What are you implying here? Only the "smart guys" get to post? Quote Link to comment Share on other sites More sharing options...
Jon Anderson Posted March 1, 2004 Author Share Posted March 1, 2004 http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=3064482197&category=3280 This was same product posted in December. The seller is West coast distributor. He has a number of posts on Audio Asylum (tubes) and those guys have good things to say about the distributor. I've tried the amp into a dedicated circuit with nothing else connected and nothing else on in the house. 4 ft cables to Klipschorns on main floor and to my Cornwalls in the basement. Same hum... Quote Link to comment Share on other sites More sharing options...
analogman Posted March 1, 2004 Share Posted March 1, 2004 garymd, Take it for what you will Brother. Analogman Quote Link to comment Share on other sites More sharing options...
Allan Songer Posted March 1, 2004 Share Posted March 1, 2004 Am I missing something? How is this amp Jolida based? Just wondering . . . Quote Link to comment Share on other sites More sharing options...
garymd Posted March 1, 2004 Share Posted March 1, 2004 Nevermind. Not worth it. Quote Link to comment Share on other sites More sharing options...
mobile homeless Posted March 1, 2004 Share Posted March 1, 2004 Ohhhhh. You got that New Kailin amp. Who told you this was a modified Jolida? While it's definitely from China, I wouldnt assume it was a modified Jolida at all. Kailin is part of the CATIC group but this layout has very little to do with most of the Jolida EL-34 amps. None of the Jolida use the 6SN7 except the 801. And this is not the same circuit as that either from the looks of it. I will tell you straight off that those 6SN7 are definitely not the best in the world, in fact, far from it. REgardless, you should not be getting hum from this amp to this level. I think I might have planted the connection with Jolida with an earlier post on Kailin showing the Jolida 202a and the similarities with an early Kailin. I would definitely consider sending this amp back if a reason does not surface. I think this is a really new model as well as I havent seen too many comments on Kailin option. I know some of their models in the past had some service issues but that was awhile back. And I really think this has nothing to do with Jolida's models. kh Quote Link to comment Share on other sites More sharing options...
Jon Anderson Posted March 1, 2004 Author Share Posted March 1, 2004 Kelly you're right about my assumption on the Kailin / Jolida connection from your prior post. I never said it was a modified Jolida - just that it hummed. Quote Link to comment Share on other sites More sharing options...
mike stehr Posted March 1, 2004 Share Posted March 1, 2004 Maybe it's the little television. You get cable with that? Quote Link to comment Share on other sites More sharing options...
Tom Mobley Posted March 1, 2004 Share Posted March 1, 2004 jeez, we could watch the game.... Quote Link to comment Share on other sites More sharing options...
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