Common Ground Issue?

fafaafooie50

I just bought a Butler TDB 2250 Amp and it causes my SDA SRS 2.3 to make all sorts of horrible sounds with the SDA Cable connected. Sounds great when disconnected.

I am assuming it is due to not having a common but I know very little about this Amp and only slightly more how the SDA works.

Butler said "Each channel is separate. It's basically 2 monoblocks in a single chassis"

Is there a way to make it work properly with the SDA Cable? I'd hate to have to use them without the SDA, nor do I want to sell the Amp at this point.

Any ideas?

F1nut

You need to build a Dreadnought, which is an isolation transformer. A search here will turn up all kinds of hits.

tonyb

Do not use that amp with those speakers. I've had that amp, loved it too btw. You need a dreadnaught, put that in the search bar and read up.

fafaafooie50

Thank you guys!

F1nut

If you have any specific questions during your research, don't hesitate to ask.

fafaafooie50

F1nut wrote: »

If you have any specific questions during your research, don't hesitate to ask.

On a scale of 1-10, one being idiot proof and 10 being really complicated where does building one of these fall? On a handy scale I'm about a 6.5-7

Is it possible to just buy one somewhere? I searched the classifieds and there didn't seem to be any currently for sale. I have a pin blade style SDA cable on my 2.3's

F1nut

It's pretty darn easy. Order the 800V transformer from Avel, part #Y236906. You'll need to find an enclosure to put it in. Use non-magnetic mounting hardware. For the connections most use Neutrik SpeakOn for the enclosure and to replace the pin/blade socket on the binding post plate. I highly recommend the NLT4FX-BAG and the NL4MP-UC.

Transformer wires are connected as follows.
Right pin - red/yellow +
Right blade - black/orange -
Left pin - grey/brown +
Left blade - blue/violet -

tonyb

You might occasionally see one pop up for sale in the flea market here, but that's a rare occurrence and if you need it now, like you do, follow F1NUT's advice. Good luck to you and welcome BTW.

You can also post in the "wanted" section for one, that's probably the fastest way to see if anyone has one laying around.

FTGV

fafaafooie50 wrote: »

I just bought a Butler TDB 2250 Amp and it causes my SDA SRS 2.3 to make all sorts of horrible sounds with the SDA Cable connected. Sounds great when disconnected.

I am assuming it is due to not having a common but I know very little about this Amp and only slightly more how the SDA works.

Butler said "Each channel is separate. It's basically 2 monoblocks in a single chassis"

Is there a way to make it work properly with the SDA Cable? I'd hate to have to use them without the SDA, nor do I want to sell the Amp at this point.

Any ideas?

Even though it's configured as a dual mono unit it doesn't appear to be a bridged/balanced design. Ask Butler if the negative speaker binding posts are at ground potential and if they can be joined together with a piece of wire to make it common ground..

fafaafooie50

F1nut wrote: »

It's pretty darn easy. Order the 800V transformer from Avel, part #Y236906. You'll need to find an enclosure to put it in. Use non-magnetic mounting hardware. For the connections most use Neutrik SpeakOn for the enclosure and to replace the pin/blade socket on the binding post plate. I highly recommend the NLT4FX-BAG and the NL4MP-UC.

Transformer wires are connected as follows.
Right pin - red/yellow +
Right blade - black/orange -
Left pin - grey/brown +
Left blade - blue/violet -

I've been searching like crazy for a thread specifically on the exact how to build a Dreadnaught. What should I pop in the search bar and what forum?

pitdogg2

Here you go This was mine and @BDT bought it and never used it. You would not need to do anything to the binding post, plug and play.


https://forum.polkaudio.com/discussion/188817/800va-dreadnaught-with-case-and-cables#latest

fafaafooie50

pitdogg2 wrote: »

Here you go This was mine and @BDT bought it and never used it. You would not need to do anything to the binding post, plug and play.


https://forum.polkaudio.com/discussion/188817/800va-dreadnaught-with-case-and-cables#latest

I saw that and I believe I sent him a DM already. Plug and play would be awesome.

fafaafooie50

pitdogg2 wrote: »

Here you go This was mine and @BDT bought it and never used it. You would not need to do anything to the binding post, plug and play.


https://forum.polkaudio.com/discussion/188817/800va-dreadnaught-with-case-and-cables#latest

This is the response I received from Butler ...

"The channels are isolated basically to prevent ground loops.
As long as ground integrity is maintained, (- to -) you should be able to tie the 2 negative speaker posts together without damaging the amp.
Try it out at low power levels first and if you don't get oscillation or ground loop hum, you should be good to go.
And... not it's not a balanced output. It's single ended."

So that sounds like a can do. Safe to use a piece of speaker wire?? I have some 14 g I could use laying around.

pitdogg2

Yes Speaker wire is fine. The 800va Dreadnought will be better in the long run. I have seen several members here who had said that strapping the negatives together introduced a little noise on some amps. The dreadnought will bring more to the table if you ever get another amp or monoblocs. You can use the dreadnought on common ground amps as well it helps with better sound for sure.


get your read on

https://forum.polkaudio.com/search?Search=dreadnought

txcoastal1

I agree
The better way would be the dreadnought

Rooster just sent TroyD a FB message

fafaafooie50

pitdogg2 wrote: »

Yes Speaker wire is fine. The 800va Dreadnought will be better in the long run. I have seen several members here who had said that strapping the negatives together introduced a little noise on some amps. The dreadnought will bring more to the table if you ever get another amp or monoblocs. You can use the dreadnought on common ground amps as well it helps with better sound for sure.


get your read on

https://forum.polkaudio.com/search?Search=dreadnought

Well this will probably give me a better idea which amp I prefer more the Butler or the Denon. I will probably sell the loser. Right now I prefer the Denon but that has SDA working so not a fair comparison.

I'm not opposed to the dreadnaught especially if I don't have to build it.

tonyb

I tried this amp with Sda's, they don't jive together . The topography of the amp is not conducive to the Sda design. I'm not even sure a dreadnought would help but I never tried one with that amp.

F1nut

Adding to the above, while strapping can work with some amps it doesn't sound as good as using the Dreadnought.

Fafa.....you posted to the activity wall. To send a PM click on the user name, then click on message at the top right corner.

Hermitism

F1nut wrote: »

Fafa.....you posted to the activity wall. To send a PM click on the user name, then click on message at the top right corner.

Here you go:

F1nut

fafaafooie50 wrote: »

F1nut wrote: »

It's pretty darn easy. Order the 800V transformer from Avel, part #Y236906. You'll need to find an enclosure to put it in. Use non-magnetic mounting hardware. For the connections most use Neutrik SpeakOn for the enclosure and to replace the pin/blade socket on the binding post plate. I highly recommend the NLT4FX-BAG and the NL4MP-UC.

Transformer wires are connected as follows.
Right pin - red/yellow +
Right blade - black/orange -
Left pin - grey/brown +
Left blade - blue/violet -

I've been searching like crazy for a thread specifically on the exact how to build a Dreadnaught. What should I pop in the search bar and what forum?

This might give you some idea. This one is the custom special order 1000V transformer, but the 800V is similar.
https://forum.polkaudio.com/discussion/142058/a-slightly-different-take-on-the-dreadnought

fafaafooie50

F1nut wrote: »

fafaafooie50 wrote: »

F1nut wrote: »

It's pretty darn easy. Order the 800V transformer from Avel, part #Y236906. You'll need to find an enclosure to put it in. Use non-magnetic mounting hardware. For the connections most use Neutrik SpeakOn for the enclosure and to replace the pin/blade socket on the binding post plate. I highly recommend the NLT4FX-BAG and the NL4MP-UC.

Transformer wires are connected as follows.
Right pin - red/yellow +
Right blade - black/orange -
Left pin - grey/brown +
Left blade - blue/violet -

I've been searching like crazy for a thread specifically on the exact how to build a Dreadnaught. What should I pop in the search bar and what forum?

This might give you some idea. This one is the custom special order 1000V transformer, but the 800V is similar.
https://forum.polkaudio.com/discussion/142058/a-slightly-different-take-on-the-dreadnought

Thanks!

fafaafooie50

F1nut wrote: »

Adding to the above, while strapping can work with some amps it doesn't sound as good as using the Dreadnought.

Fafa.....you posted to the activity wall. To send a PM click on the user name, then click on message at the top right corner.

Got it.

fafaafooie50

So binding the two posts has seemingly worked but it's too late to really test the sound quality. I'm learning towards it being a little scratchy but hard to say without some more volume. Will revisit in the morning.
I really want to like this amp...

FTGV

fafaafooie50 wrote: »

pitdogg2 wrote: »

Here you go This was mine and @BDT bought it and never used it. You would not need to do anything to the binding post, plug and play.


https://forum.polkaudio.com/discussion/188817/800va-dreadnaught-with-case-and-cables#latest

This is the response I received from Butler ...

"The channels are isolated basically to prevent ground loops.
As long as ground integrity is maintained, (- to -) you should be able to tie the 2 negative speaker posts together without damaging the amp.
Try it out at low power levels first and if you don't get oscillation or ground loop hum, you should be good to go.
And... not it's not a balanced output. It's single ended."

So that sounds like a can do. Safe to use a piece of speaker wire?? I have some 14 g I could use laying around.

That's what I figured. That will at least get you in the SDA game .

westmassguy

If you plan to roll your own, this is the case I use:
https://www.digikey.com/product-detail/en/1550NBK/HM1201-ND/2211551

tonyb

fafaafooie50 wrote: »

So binding the two posts has seemingly worked but it's too late to really test the sound quality. I'm learning towards it being a little scratchy but hard to say without some more volume. Will revisit in the morning.
I really want to like this amp...

Then use it with different speakers. I've used it with Legacy Focus 20/20 speakers with very good results. Sometimes no matter what you do, certain things just don't play well together.

fafaafooie50

tonyb wrote: »

fafaafooie50 wrote: »

So binding the two posts has seemingly worked but it's too late to really test the sound quality. I'm learning towards it being a little scratchy but hard to say without some more volume. Will revisit in the morning.
I really want to like this amp...

Then use it with different speakers. I've used it with Legacy Focus 20/20 speakers with very good results. Sometimes no matter what you do, certain things just don't play well together.

I've been waiting decades for these speakers so they are staying for a while...

But after putting in 5 plus hours of listening to my favorite music I am very satisfied with the Butler. My initial concerns of scratchy at low level was due to using a Gas Station Greatest Hits CD of RUSH. I didn't realize the poor quality being it mostly plays in my car. I generally play vinyl at home but let's face it the CD is much easier to deal with while doing other things besides listening to records.
It has endless power for my needs and has a nice neutral sound. I think my Denon POA 2800 is a little brighter but need to do a swap back.

I figured out a way to do faster swaps back and forth so should be easier to compare. But if I never had the Denon and this was my first Amp I'd have a large smile on my face. Especially for what I paid for it.

I'm up in the air on the dreadnaught. I can't imagine it will sound that much better???

Thanks for all of the input!!

F1nut

It will sound better with the Dreadnought. Everyone that doubted it after installing a Dreadnought has kicked themselves for not doing it sooner.

FTGV

fafaafooie50 wrote: »

I've been waiting decades for these speakers so they are staying for a while...

Enjoy.

fafaafooie50

F1nut wrote: »

It will sound better with the Dreadnought. Everyone that doubted it after installing a Dreadnought has kicked themselves for not doing it sooner.

Duly noted. If I can find one reasonably priced I might snatch it up. It will just be hard to swallow paying more for that than I did the amplifier.

pitdogg2

I have 3x more wrapped up in my speakers 2.3tl's than my amplifier cost me....

That one I linked to is legit and priced right if Troy ever comes up for air.