I have always been slightly concerned that my Croft amplifier cases although perfectly adequate for the job are made of fairly thin steel especially the top lid which has slots cut into it to allow valve ventilation. However because the top lid is thin it vibrates both from airborne sources and very slightly from a buzzing toroid.
Anyone got any suggestions of what I can use on the inside of the steel lid to dampen it down? My current solution is to put something heavy on top.
I have always been slightly concerned that my Croft amplifier cases although perfectly adequate for the job are made of fairly thin steel especially the top lid which has slots cut into it to allow valve ventilation. However because the top lid is thin it vibrates both from airborne sources and very slightly from a buzzing toroid.
Anyone got any suggestions of what I can use on the inside of the steel lid to dampen it down? My current solution is to put something heavy on top.
Hi James,
Send me your address and I'll post an A4 sheet of Silent Coat to you. It's basically the same as Dynamat and that first link above... and should be used judiciously. You'll probably only need one or two 10mm discs.
I have always been slightly concerned that my Croft amplifier cases although perfectly adequate for the job are made of fairly thin steel especially the top lid which has slots cut into it to allow valve ventilation. However because the top lid is thin it vibrates both from airborne sources and very slightly from a buzzing toroid.
Anyone got any suggestions of what I can use on the inside of the steel lid to dampen it down? My current solution is to put something heavy on top.
Hi James,
Send me your address and I'll post an A4 sheet of Silent Coat to you. It's basically the same as Dynamat and that first link above... and should be used judiciously. You'll probably only need one or two 10mm discs.
Thats very generous of you. Thank you. I will send you a PM.
That has been suggested and certainly may do. The case is mainly vibrating through airborne vibration I think but a DC blocker would cure the toroid buzzing.
That has been suggested and certainly may do. The case is mainly vibrating through airborne vibration I think but a DC blocker would cure the toroid buzzing.
It's probably just a rattly case. Mount the mains traffo remotely, bolt it to a perspex disc and glue that to 10mm thick foamed neoprene rubber with pu glue, and glue the whole thing to the chassis.
That's how the traffo in my neurochromes are mounted, absolutely zero chassis vibration.
I wouldn't throw them about, but short of leaving them upside down I'm not worried about them coming unstuck.
When I first used one it seemed that a little of the edge sharpness was gone and I mentioned that to Nick @lda. He said it may be that what I was used to was overshoot and to listen for week or two before deciding. Of course there were capacitors to break in as well. I ended up agreeing that could be it and have been happy for years since whilst enjoying good handling of the leading edges.
From LC Audio it's a EUR30 experiment not like £700+ some are asking.
The transformer is only causing very slight vibration, most of the case vibration is coming from the speakers being close.
A DC blocker wont do anything if it's being caused by the speaker.
Also, the Transformer is likely to be vibrating due to the laminations. Could also possibly be from being rated for 230v and your home supply being at least 240v. Some transformers do not like more than 230v.
I would suggest using that damping mat and seeeing how you get on. If you can hear the traffo buzzing away, change them for proper spec ones. It's the only real long term cure, and i expect the Crofts are going to be long term in your system.
The transformer is only causing very slight vibration, most of the case vibration is coming from the speakers being close.
A DC blocker wont do anything if it's being caused by the speaker.
Also, the Transformer is likely to be vibrating due to the laminations. Could also possibly be from being rated for 230v and your home supply being at least 240v. Some transformers do not like more than 230v.
I would suggest using that damping mat and seeeing how you get on. If you can hear the traffo buzzing away, change them for proper spec ones. It's the only real long term cure, and i expect the Crofts are going to be long term in your system.
Of course a DC blocker is only if the vibration is from the transformer and if it's due to a little DC on the mains. I didn't notice, is that a laminated core transformer next to the toroidals? I was thinking of toroidals, but in any case it seems there are several possibilities.
A DC blocker wont do anything if it's being caused by the speaker.
Also, the Transformer is likely to be vibrating due to the laminations. Could also possibly be from being rated for 230v and your home supply being at least 240v. Some transformers do not like more than 230v.
I would suggest using that damping mat and seeeing how you get on. If you can hear the traffo buzzing away, change them for proper spec ones. It's the only real long term cure, and i expect the Crofts are going to be long term in your system.
Of course a DC blocker is only if the vibration is from the transformer and if it's due to a little DC on the mains. I didn't notice, is that a laminated core transformer next to the toroidals? I was thinking of toroidals, but in any case it seems there are several possibilities.
DC blockers are not the be all and end all. They certainly kill musicality.
not always . they have different effects . i once had a puresound L10 and it made a really big enjoyable difference to its musicality [ isotek syncro ]
i agree though its not always the answer and i have had 4 isotek syncro in my time