Magnetic Compnents inc universal transformer thread

[baron55]

10 A on the heaters was for guys running a quad of KT 88's

And 5 to 6 preamp tubes on multi channel amps. The idea is to have a PT that can be used for anything.

[joey]

BTW: in Germany the wall voltage is around 235V +/- 5V.

With the dual primaries if you look, that can be arrainged.

[ClassicTone]

I am okay with the last design mentioned by Joey with the 10A on the heaters and as he mentions, it has the dual primary that can be configured for 240 (or lower at 230V if necessary) for Germany. Robert.....it will have heavier brackets instead of the mounting "feet" that are shown the the photo of the 40-18023. Also, I'm not sure about the shipping costs or the method of shipping to Germany yet since we do not have a production design of this yet since we are trying now to finalize this. Triode Electronics will be the distributor on this when we make these available.

We will proceed with this unless I hear serious objections? Okay?

We need to finalize the design and cost it out if it is okay with everyone. It will take a few weeks to produce and bring to market since we need to order some of the materials for this part, produce these and get these to our distributor, Triode Electronics.

Joe Janisch
ClassicTone By Magnetic Components, Inc.

[joey]

I am okay with the last design mentioned by Joey with the 10A on the heaters and as he mentions, it has the dual primary that can be configured for 240 (or lower at 230V if necessary) for Germany. Robert.....it will have heavier brackets instead of the mounting "feet" that are shown the the photo of the 40-18023. Also, I'm not sure about the shipping costs or the method of shipping to Germany yet since we do not have a production design of this yet since we are trying now to finalize this. Triode Electronics will be the distributor on this when we make these available.

We will proceed with this unless I hear serious objections? Okay?

We need to finalize the design and cost it out if it is okay with everyone. It will take a few weeks to produce and bring to market since we need to order some of the materials for this part, produce these and get these to our distributor, Triode Electronics.

Joe Janisch
ClassicTone By Magnetic Components, Inc.

Joe, it is a go! do you want me to send a bigger version of the schematic? and drum up some hype?

[ClassicTone]

Joey,

A larger drawing would be fantastic!

Any help to market and sell this would be very much appreciated!

Can you please give me a good description of this item and what it is intended to be used for ...which tubes?...wattage?...etc.... all that good stuff. Can I use .."Sloclone forum approved" or "in conjuntion with Sloclone Forum members"...or something of that nature...etc.? Can it still be used as a 100W Marshall upgrade as discussed or is it now too big? Other OEM amplifier upgrades as well?

I will use this information on our web site page for this part when we offer it.

As mentioned, this will be the 1st part offered of our new "Project amplifier" transformer category for ClassicTone. If successful, I would love to work with everyone here again on suggestions on other items as well.

Thanks Joey and everyone else here for the help and great suggestions! We will be proud and happy to bring this to you soon!

[robert]

Hi Baron,

regarding the max. current of the 6,3V heater winding:

4x 1,6A (KT88) = 6,4A
6x 0,3A (ECC83) = 1,8A

Total = 8,2A

So let's say, 8,5A would be fairly enough IMHO.
The problem is: too much overheating shortens simply the life of the tubes (too much underheating does this also).
That's the reason I've voted for the 6,1Volt under the full heater load because a healthy "balance" (let's say 6,1V to 6,5V)

E.g.: imagine if one would use only 4x 6L6 and only 3 preamp tubes (take a look at the datasheet for their heater currents)- this would cause much less load to the 6,3V winding, and therefore the voltage will rise up, causing a more or less tube filament overheating.

Regards

Robert

[joey]

Hi Baron,

regarding the max. current of the 6,3V heater winding:

4x 1,6A (KT88) = 6,4A
6x 0,3A (ECC83) = 1,8A

Total = 8,2A

So let's say, 8,5A would be fairly enough IMHO.
The problem is: too much overheating shortens simply the life of the tubes (too much underheating does this also).
That's the reason I've voted for the 6,1Volt under the full heater load because a healthy "balance" (let's say 6,1V to 6,5V)

E.g.: imagine if one would use only 4x 6L6 and only 3 preamp tubes (take a look at the datasheet for their heater currents)- this would cause much less load to the 6,3V winding, and therefore the voltage will rise up, causing a more or less tube filament overheating.

Regards

Robert

You guys are impossible to please! how about we go back to the 6.1- 6.2, and just not tell anybody. ...
The other issue is variance in wall vac, which may make the bigger impact. Some people in the us still have 117Vac, I have 121Vac, my old place had 125Vac. how about the compromise be on 6.2 with the clause "guaranteed to be within in tolerance range under ideal operating conditions"......... How about I just make the call and surprise you. one thought though Slightly higher is always easier to work around than slightly lower.

[baron55]

Hi Baron,

regarding the max. current of the 6,3V heater winding:

4x 1,6A (KT88) = 6,4A
6x 0,3A (ECC83) = 1,8A

Total = 8,2A

So let's say, 8,5A would be fairly enough IMHO.
The problem is: too much overheating shortens simply the life of the tubes (too much underheating does this also).
That's the reason I've voted for the 6,1Volt under the full heater load because a healthy "balance" (let's say 6,1V to 6,5V)

E.g.: imagine if one would use only 4x 6L6 and only 3 preamp tubes (take a look at the datasheet for their heater currents)- this would cause much less load to the 6,3V winding, and therefore the voltage will rise up, causing a more or less tube filament overheating.

Regards

Robert

Robert, I see your point.

The above heater current draw KT88 and 12AX7''s are datasheet values which were derived many years ago. I have found that most of the current production tubes pull much more than datasheet spec especially the chinese tubes unless you use NOS glass.
The data sheet values are good for ball park estimates, but I always have a higher current capacity.
Most datasheets allows for heater voltage to vary +/- .6 volts when running at the 6.3 volt standard.

But the real issue is this. Here in the US the Mains voltages vary from 117VAC to 127VAC, so the large variance in mains voltages really negate the difference you would see with load changes on voltages. There is significantly more of a change with the mains voltage fluctuation.

So even at 8.5 amps, some guys are going to have high or low voltages wheter they are 6, 6.1 or 6.3

Basically, your never going to get the heater voltages right on unless you have a line regulator controlling the mains input.

But the PT is already done it looks like and thanks to Joey who got the ball rolling, this is great!

[ClassicTone]

My engineer's biggest objection to the original design was when he saw the 6.2VAC. The 6.3 is more of the standard and if we start using odd ratings, they may not sell except to a select few. For what it's worth, my engineer did like the last design of Joey's with the 6.3VAC and 10A. I'll hold this up until you all decide.

Joe Janisch
ClassicTone By Magnetic Components, Inc.

[baron55]

Joe I think it is a go:)

[Roe]

the only worry with the heater winding is that you might get too high voltages with 6l6s. but perhaps 6.3v at 9A will work

[joey]

Okay, here are my thoughts about the last pending issue at hand. there is never going to be a way to get this perfect. there will always be too much variance in either wall vac or load. If it is under spec'd, there is no easy way to fix it. If it is over spec'd for the job, a simple single resistive load can be placed on the heater supply to bring it down to where it needs to be. I have also seen accounts of not only CP chinese tubes, but CP russian valves as well particularly new sensor, that are a bit more current hungry than their older counter parts, so it is something to keep in mind as well.

[joey]

Okay, here are my thoughts about the last pending issue at hand. there is never going to be a way to get this perfect. there will always be too much variance in either wall vac or load. If it is under spec'd, there is no easy way to fix it. If it is over spec'd for the job, a simple single resistive drop can be placed on the heater supply to bring it down to where it needs to be. I have also seen accounts of not only CP chinese tubes, but CP russian valves as well particularly new sensor, that are a bit more current hungry than their older counter parts, so it is something to keep in mind as well.

[guns4hire34]

Is the Classic Tone 40-18026 a direct bolt-in to a Metro 12000 series chassis or do I have to drill new holes???

[ClassicTone]

Hi gunsforhire4,

I do not honestly know the mounting dimensions for Metro's 12000 series chassis and do not believe they post them.

The specs on the mountings for our ClassicTone # 40-18026 are as follows:

http://www.classictone.net/40-18026.pdf" onclick="window.open(this.href);return false;

Does anyone here know what Metro's 12000 series chassis hole dimensions are for the output transformer and can answer this question? Please advise. Thank you!

Joe Janisch
ClassicTone By Magnetic Components, Inc.