Hello,
This is my first post. I have an ad140 single channel amp that I got about four years ago and I have only replaced the tubes once, so I have a few questions if anyone else can offer advice. When i took the amp to get re-tubed and biased (Aside from costing an arm and a leg, has anyone done this themselves?) last year, the store said the only tubes they could find that were suitable for a 140 watt amp were electro-harmonix tubes. I have had these for a while now and I don't really enjoy the sound of them, anyone have any personal suggestions or advice to offer? and do the pre-amp tubes really affect the sound of the amplifier a great deal? thanks for any advice.
AD 140 Tube Help!
Moderator: bclaire
-
Andy H.
- Duke of Orange
- Posts: 9965
- Joined: Thu Jan 29, 2004 8:50 am
- Location: Amsterdam, Netherlands.
Hello Basin Alders. You might want to check this recent discussion:http://www.orangeamps.com/forum/topic.asp?TOPIC_ID=1388
The quality of EL34s has improved in recent years apparently, and there certainly are viable alternatives to the EH's.
Yes, pre amp tubes can make a lot of difference. Higher or lower gain and output being the main ones, but tonally they are not all alike. Fortunately you can just swap out pre amp tubes without worrying about the expense of biasing, and even the really good ones are much cheaper then power tubes, so try a few and find what works for you.
Biasing you amp for new power tubes just <b>isn't</b> a DIY job. Make friends with a good amp tech!
Andy.
Edited by - Andy H. on 30 Jul 2004 08:47:35
The quality of EL34s has improved in recent years apparently, and there certainly are viable alternatives to the EH's.
Yes, pre amp tubes can make a lot of difference. Higher or lower gain and output being the main ones, but tonally they are not all alike. Fortunately you can just swap out pre amp tubes without worrying about the expense of biasing, and even the really good ones are much cheaper then power tubes, so try a few and find what works for you.
Biasing you amp for new power tubes just <b>isn't</b> a DIY job. Make friends with a good amp tech!
Andy.
Edited by - Andy H. on 30 Jul 2004 08:47:35
Only dimly aware of existence, a dimly existing awareness...
You get a wonderful view from the point of no return.
You get a wonderful view from the point of no return.
-
fiveightandten
- Orange Master
- Posts: 3845
- Joined: Sat Apr 05, 2003 6:18 pm
- Location: Connecticut, USA
<BLOCKQUOTE id=quote><font size=1 face="Verdana, Arial, Helvetica" id=quote>quote:<hr height=1 noshade id=quote>
Hello,
This is my first post. I have an ad140 single channel amp that I got about four years ago and I have only replaced the tubes once, so I have a few questions if anyone else can offer advice. When i took the amp to get re-tubed and biased (Aside from costing an arm and a leg, has anyone done this themselves?) last year, the store said the only tubes they could find that were suitable for a 140 watt amp were electro-harmonix tubes. I have had these for a while now and I don't really enjoy the sound of them, anyone have any personal suggestions or advice to offer? and do the pre-amp tubes really affect the sound of the amplifier a great deal? thanks for any advice.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
I'm not sure where you're located, but unless it's out in the middle of nowhere, biasing shouldn't cost you a whole lot. If you're in the states, a new set of EL-34's shouldn't run you more than $70 or so. And if you pay someone more than $30-40 TOPS to bais it, you're getting ripped off.
You most certainly can learn to do it yourself. But it involves being comfortable working around high voltages. You also need to have a steady hand, as i've seen more than one person touch a multimeter lead to 2 pins at once and short a tube out.
Read this article for more info on what biasing entails...
http://www.duncanamps.com/technical/lvbias.html
As far as EH's being the only tube suitable for a 140W amp. That's a load of garbage. EH's actually aren't very sturdy tubes, though they're better than they used to be. There are current production tubes like SED's and JJ's that can handle FAR more abuse than the EH's. Both SED's and JJ's can take higher plate voltages, and a higher static plate dissipation wattage. EH's will pop out running in idle current draw situations where SED's or JJ's would be fine.
The EH EL-34's are nice sounding tubes. But they're no tougher than Sovteks, and certainly not as roubust as the SED's or JJ's.
The other thing is that I highly doubt that the AD140 is actually putting out 140W. At a reasonable bias current, the amp would have to have an insane plate voltage. I don't have the charts in front of me, but for an amp to put out 140W of clean power...i'm not even sure if it's possible with 4 EL-34's. Maybe 140W totally distorted. But the plate voltage would probably have to be up around 600V.
At any rate...depending on what it is about the EH's that you're not happy about. I may recommend the SED's, as they're made better, and sound better IMO. Then again...how hot or cold that tech set your bias could have everything to do with how the amp sounds. SO it may not be the tubes you don't like, as much as how the bias is set wit them in the amp.
Hope that helps,
-Nick
Hello,
This is my first post. I have an ad140 single channel amp that I got about four years ago and I have only replaced the tubes once, so I have a few questions if anyone else can offer advice. When i took the amp to get re-tubed and biased (Aside from costing an arm and a leg, has anyone done this themselves?) last year, the store said the only tubes they could find that were suitable for a 140 watt amp were electro-harmonix tubes. I have had these for a while now and I don't really enjoy the sound of them, anyone have any personal suggestions or advice to offer? and do the pre-amp tubes really affect the sound of the amplifier a great deal? thanks for any advice.
<hr height=1 noshade id=quote></BLOCKQUOTE id=quote></font id=quote><font face="Verdana, Arial, Helvetica" size=2 id=quote>
I'm not sure where you're located, but unless it's out in the middle of nowhere, biasing shouldn't cost you a whole lot. If you're in the states, a new set of EL-34's shouldn't run you more than $70 or so. And if you pay someone more than $30-40 TOPS to bais it, you're getting ripped off.
You most certainly can learn to do it yourself. But it involves being comfortable working around high voltages. You also need to have a steady hand, as i've seen more than one person touch a multimeter lead to 2 pins at once and short a tube out.
Read this article for more info on what biasing entails...
http://www.duncanamps.com/technical/lvbias.html
As far as EH's being the only tube suitable for a 140W amp. That's a load of garbage. EH's actually aren't very sturdy tubes, though they're better than they used to be. There are current production tubes like SED's and JJ's that can handle FAR more abuse than the EH's. Both SED's and JJ's can take higher plate voltages, and a higher static plate dissipation wattage. EH's will pop out running in idle current draw situations where SED's or JJ's would be fine.
The EH EL-34's are nice sounding tubes. But they're no tougher than Sovteks, and certainly not as roubust as the SED's or JJ's.
The other thing is that I highly doubt that the AD140 is actually putting out 140W. At a reasonable bias current, the amp would have to have an insane plate voltage. I don't have the charts in front of me, but for an amp to put out 140W of clean power...i'm not even sure if it's possible with 4 EL-34's. Maybe 140W totally distorted. But the plate voltage would probably have to be up around 600V.
At any rate...depending on what it is about the EH's that you're not happy about. I may recommend the SED's, as they're made better, and sound better IMO. Then again...how hot or cold that tech set your bias could have everything to do with how the amp sounds. SO it may not be the tubes you don't like, as much as how the bias is set wit them in the amp.
Hope that helps,
-Nick
'71 GRO100 || '96 OR-80 || AD30 || '64 AC-50 || AC-30TBX || Hiwatt DR504 || HI-TONE HT30
LP Standard || LP Studio || LP Custom Lite || Ric 620 || Ric 360 || MIA Tele || SG 61 RI
Who is online
Users browsing this forum: No registered users and 237 guests