SingleMalt Posted January 14, 2015 Share Posted January 14, 2015 (edited) Hey folks. So I've had two different Ashdown CTM-15 heads now (the first had a faulty VU meter and had to be replaced) in the form of the DH-115-C110 drophead combo units (nice bit of kit by the way). Both have [b]stupid [/b]amounts of hum when the volume or gain are turned up. This is true with no bass plugged in at all and with a bass hooked up. The hum does get worse with a bass though (It's a very well shielded Precision, never had any issues with hum with it before). With the gain below 9 o'clock and the volume bellow 12 its not too bad, just a little hum. Raising just the volume to max gives a boat load of hiss and hum, raising the gain as well produces an insane amount. She still has the stock Chinese valves although I'm planning on swapping them for some NoS Sovtek EL84s and a GT ECC83/5751 soon. I did find another thread on here a week or so ago where someone mentioned hum with their CTM-15 but I cannot find it again for the life of me. Any suggestions as to what could be causing this? Do you think I need to raise this issue with Ashdown? Like I said both units I've had have the same problem. Cheers! Edited January 14, 2015 by SingleMalt Quote Link to comment Share on other sites More sharing options...
Ashdown Engineering Posted January 14, 2015 Share Posted January 14, 2015 Sounds like it could be a noisy valve as shouldn't be particularly hissy, fire an email to [email protected] and let's see what we can do Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted January 14, 2015 Author Share Posted January 14, 2015 (edited) Will do, thanks! Edit: Email sent. Edited January 14, 2015 by SingleMalt Quote Link to comment Share on other sites More sharing options...
VTypeV4 Posted January 15, 2015 Share Posted January 15, 2015 [quote name='Ashdown Engineering' timestamp='1421274831' post='2659402'] Sounds like it could be a noisy valve as shouldn't be particularly hissy, fire an email to [email protected] and let's see what we can do [/quote] Ashdown really should be complemented on their excellent customer service. I've had good service from british companies in the past notably Trace, Celestion, Cloud and Allen & Heath but it seems Ashdown go the extra mile for their customers. It's nice to see them well represented on this forum too. Top drawer, chaps. Hope the O/P gets his amp sorted. Quote Link to comment Share on other sites More sharing options...
mazdah Posted January 15, 2015 Share Posted January 15, 2015 I've never heard an amp that didn't hiss an hum like crazy with gain and master all the way up. Even the super high-tech ones do! Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted January 15, 2015 Author Share Posted January 15, 2015 [quote name='mazdah' timestamp='1421308543' post='2659546'] I've never heard an amp that didn't hiss an hum like crazy with gain and master all the way up. Even the super high-tech ones do! [/quote] Of course I expect some hum, but not this amount. Right now I've got the amp on in the next room with volume set to 3 o clock and gain at 10 o clock. I can hear the hissing through the wall (and I live in an old house with thick walls). I tried recording it with my phone but sadly you can't hear any difference between a tiny bit of hiss and loads. Rubbish phone microphones! Quote Link to comment Share on other sites More sharing options...
fretmeister Posted January 15, 2015 Share Posted January 15, 2015 Valve amps with big arse transformers are usually noisier than SS amps. It's the price you pay for having that all valve tone. But you shouldn't hear it through a wall!! Quote Link to comment Share on other sites More sharing options...
Pow_22 Posted January 15, 2015 Share Posted January 15, 2015 (edited) The CTM 15 isnt all valve tho, its a solid state front end pushing a valve power section. As a side note, id still love to try the Ashdown DP200H Edited January 15, 2015 by Pow_22 Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted January 15, 2015 Author Share Posted January 15, 2015 [quote name='Pow_22' timestamp='1421324939' post='2659820'] The CTM 15 isnt all valve tho, its a solid state front end pushing a valve power section. [/quote] I assume the ecc83 is just a phase inverter then? A little naught of Ashdown considering that they are marketed on gear shops as being all valve. This is something Ashdown need to address, their retailers should be not listing it as all valve if it's not. It was one of the reasons why I brought it (an inexpensive way to play around with valve amps), although it's not the end of the world as I do like the sound and can't tell it's not all valve from the sound. Even the manual states the preamp is an ecc83 and yet if you look at internal pictures online you can see opamps in there. Quote Link to comment Share on other sites More sharing options...
omikin Posted January 17, 2015 Share Posted January 17, 2015 I have had similar issues with mine. I did log it via Ashdown's website but had no reply so I will email Guy. Love the tone of this thing! Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted January 17, 2015 Author Share Posted January 17, 2015 [quote name='omikin' timestamp='1421495161' post='2661934'] I have had similar issues with mine. I did log it via Ashdown's website but had no reply so I will email Guy. Love the tone of this thing! [/quote] Well you may be waiting a while, I haven't heard anything back yet. I might just try swapping the valves. Quote Link to comment Share on other sites More sharing options...
omikin Posted January 18, 2015 Share Posted January 18, 2015 Keep us posted with how you get on. Quote Link to comment Share on other sites More sharing options...
TheRockinRoadie Posted January 18, 2015 Share Posted January 18, 2015 Guy has always been really quick to reply in the past when I have had questions. Maybe there's still a bit of a backlog from when they relocated to a new premises recently. I really like the CTM-15 and are looking into them as an alternative to my CTM100 for smaller gigs. I agree some clarification may be needed about the nature of the valves, but they sound great and that's the main thing. Hopefully Guy will get back to you soon! Quote Link to comment Share on other sites More sharing options...
Merton Posted January 18, 2015 Share Posted January 18, 2015 Yeah they've recently moved premises and half of the guys are now in America for NAMM so it may take a little longer than normal for a response Quote Link to comment Share on other sites More sharing options...
Bill Fitzmaurice Posted January 18, 2015 Share Posted January 18, 2015 [quote name='SingleMalt' timestamp='1421272034' post='2659333'] Both have [b]stupid [/b]amounts of hum when the volume or gain are turned up. This is true with no bass plugged in at all [/quote]That's a defect. With no bass plugged in the input is shorted and any noise is self-generated. Quote Link to comment Share on other sites More sharing options...
HowieBass Posted January 18, 2015 Share Posted January 18, 2015 I've read you can get hum from pre-amp valves using an AC supply for the heater (rather than a DC rectified supply) but this is more a circuit design issue than a fault (I think this is what affects my old WEM Westminster 15 valve combo). There are also ways of routing internal wires that minimise hum - this is obviously a manufacturing consideration. I hope whatever's the cause of the hum with your Ashdown it can be fixed easily! Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted January 18, 2015 Author Share Posted January 18, 2015 It seems unlikely to be a fault to me since both amps I've had did the exact same thing. It's not really a problem when the game is at 8 o'clock or less and volume is under 12 but where is the fun in that! Quote Link to comment Share on other sites More sharing options...
Pow_22 Posted January 22, 2015 Share Posted January 22, 2015 [quote name='SingleMalt' timestamp='1421330135' post='2659928'] I assume the ecc83 is just a phase inverter then? A little naught of Ashdown considering that they are marketed on gear shops as being all valve. This is something Ashdown need to address, their retailers should be not listing it as all valve if it's not. It was one of the reasons why I brought it (an inexpensive way to play around with valve amps), although it's not the end of the world as I do like the sound and can't tell it's not all valve from the sound. Even the manual states the preamp is an ecc83 and yet if you look at internal pictures online you can see opamps in there. [/quote] Anyone ever pulled them to task on this? All their ad's state All Valve Quote Link to comment Share on other sites More sharing options...
mazdah Posted January 23, 2015 Share Posted January 23, 2015 I think that half of the ECC83 may be V1, so the EQ is solid state... but the preamp is valve (like Eden, SWR stuff). Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted January 24, 2015 Author Share Posted January 24, 2015 (edited) [quote name='Pow_22' timestamp='1421929428' post='2666678'] Anyone ever pulled them to task on this? All their ad's state All Valve [/quote] I asked them in an email about a Month ago and haven't heard anything back. Still haven't heard anything in from their engineer about my issue. It's been 10 days now. Edited January 24, 2015 by SingleMalt Quote Link to comment Share on other sites More sharing options...
SingleMalt Posted February 5, 2015 Author Share Posted February 5, 2015 Still not a peep from from their engineer! I sent another email but still nothing. I might just swap in the valves I want to use and see if that helps, although I still don't know if changing the 'pre-amp' valve will make a difference. I've heard that it's just a phase inverter and I've also heard that it actually is the pre-amp and the op-amps inside are for the EQ. I may give them a call in the morning if I get the time. Quote Link to comment Share on other sites More sharing options...
basskit_case Posted July 6, 2015 Share Posted July 6, 2015 Did you ever hear back from Ashdown? Quote Link to comment Share on other sites More sharing options...
Pow_22 Posted July 6, 2015 Share Posted July 6, 2015 From Dissa of this parish:- I got a really quick answer from the Ashdown Support: [i]"The Preamp on the CTM15 is solid State driving a tube back end[/i]..." Quote Link to comment Share on other sites More sharing options...
jammys Posted February 21, 2016 Share Posted February 21, 2016 [quote name='SingleMalt' timestamp='1423159754' post='2681626'] Still not a peep from from their engineer! I sent another email but still nothing. I might just swap in the valves I want to use and see if that helps, although I still don't know if changing the 'pre-amp' valve will make a difference. I've heard that it's just a phase inverter and I've also heard that it actually is the pre-amp and the op-amps inside are for the EQ. I may give them a call in the morning if I get the time. [/quote] Hi did you get any joy from Ashdown? I'm now have the same hissing issues with my CTM 15 Quote Link to comment Share on other sites More sharing options...
ppaul Posted February 21, 2016 Share Posted February 21, 2016 I have the CTM15 no hum or issues, I'm hoping to have a LB 30 later in the week which does have 2 preamp tubes gonna be interesting how they compare side by side Quote Link to comment Share on other sites More sharing options...
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