Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: GlideOn on August 16, 2024, 08:26:11 am
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New here, but tinkering with amps for some time.
I'm currently overhauling this decade old AX84 based SEL amp to make it Parallel EL34 and while I'm competent with my knowledge and working abilities, I'm a bit stumped at the moment when it comes to the power transformers.
I needed more power to run higher current and voltage to a pair of EL34s, so I got some Toroidals from AnTek. Also got the very nice steel covers for them.
The MS-30W25 (2.5k) Output Transformer is pretty similar coloring to the Hammond units, save for no 16ohm tap. No real issues there.
However the other AS-2T300 Power Transformer gives me slight pause.
There were no guides or diagrams included in my order and the one on the net is clearly an older diagrams as it has Green or Orange 6.3v wires whereas mine does not.
I've emailed AnTek and I can't get a clear answer, also whomever the support specialist is I'm not sure English is their primary language...
The wire colors are as follows:
Primary:
- Red
- Black
- Red
- Black
- Purple
Secondaries:
- Brown
- Brown
- Blue
- Blue
- White
- Yellow
- White
- Yellow
There are no Center Taps for the Heater Wires.
I'm pretty confident the Red+Red wire in parallel together to the (+) of the IEC power socket and the Black+Black go to the Power Switch.
Purple is shield/ground.
I'm pretty confident the White+Yellow go to the outer two diodes in a Full Wave; rear diodes parallel to create Center Tap ground and forward diode parallel to create the B+ going directly to the Standby Switch (protected by 3w 47k surge resistor in case of in-rush).
Other White/Yellow get insulated (individually) and capped off, right?
What I'm not so confident in is the Brown/Brown and Blue/Blue.
I'm not sure if the Brown/Brown go together? Or the Blue/Brown go together?
Multimeter continuity shows Brown/Brown connect and Blue/Blue connect.
I only need one of them to power 2x EL34s and 3x 12AX7s
But in short, has anyone who has used AnTeks in past 10 years figured out the new wiring colors?
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Screenshot attached.
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Screenshot attached.
This is the old one, blurry as it is
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Clearer pic attached. Your testing shows continuity between the blue and brown wires. This indicates that the wires of like colors are on opposite ends of the same winding. There would be no continuity otherwise. Make sense? The remaining windings are obvious from there. There are different ways to wire up the high voltage taps (yellow/white), so it would help the folks here if you sketch what you want to do including the PT, HT supply, Power Tubes, and OT. I do not know about you, but I find it easier to follow a plan.
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Clearer pic attached. Your testing shows continuity between the blue and brown wires. This indicates that the wires of like colors are on opposite ends of the same winding. There would be no continuity otherwise. Make sense? The remaining windings are obvious from there. There are different ways to wire up the high voltage taps (yellow/white), so it would help the folks here if you sketch what you want to do including the PT, HT supply, Power Tubes, and OT. I do not know about you, but I find it easier to follow a plan.
Plan is to wire it up according to an accurate, current diagram, hence my post.
Continuity means the Brown/Brown or Blue/Blue pairing should be used? Not the Brown/Blue?
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I'm currently overhauling this decade old AX84 based SEL amp
post that schematic here, most of us don't have that amp memorized
post a pic of the original PS transformer as originally wired
I needed more power to run higher current and voltage
what values are your "new" requirements?
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Here's the full datasheet (from https://www.antekinc.com/as-2t300-200va-300v-tube-transformer/)
Further down the page is this chart:
Electrical Characteristics
Outputs 4x
Power 200VA
Output Voltage Current
300V 0.33A
300V 0.33A
6.3V 4A
6.3V 4A
I think you only need one of the HV windings to supply 300 VAC at 330 mA, assuming you are using a bridge rectifier.
I think you'll only need one of the heater windings to power your tube complement (datasheet says they each output 4A).
If you have continuity from blue to blue, then that is one winding. If you also have continuity from brown to brown, that is the other winding.
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Here's the full datasheet (from https://www.antekinc.com/as-2t300-200va-300v-tube-transformer/)
Further down the page is this chart:
Electrical Characteristics
Outputs 4x
Power 200VA
Output Voltage Current
300V 0.33A
300V 0.33A
6.3V 4A
6.3V 4A
I think you only need one of the HV windings to supply 300 VAC at 330 mA, assuming you are using a bridge rectifier.
I think you'll only need one of the heater windings to power your tube complement (datasheet says they each output 4A).
If you have continuity from blue to blue, then that is one winding. If you also have continuity from brown to brown, that is the other winding.
Are you certain?
I am getting conflicting advice.
This is the reply I got from AnTek and hour ago, complete with pictures (mine does not have diagram on side):
"The 1st and 3rd wires together as one of the 6.3V and 2nd and 4th wires together as another one of the 6.3V"
And yet, I am getting continuity the other way around.
Clearly the diagram they send show Blue/Blue and Brown/Brown. Neither color wires crosses each other.
Are they supposed to show continuity, being AC wires?
Should I trust this or trust my instincts in going with the continuity?
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Your meter and the transformer label and the data sheet show blue and blue as one winding. Their email instructions are for putting the two windings in parallel to get 6v at 8a. And you can do that if you like.
Hook up the primary to the wall temporarily and prove it to yourself.
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Are they supposed to show continuity, being AC wires
"Continuity" is simply open? short?
"Resistance" is a simplified way to determine "how many windings" long piece of wire has more R than short piece of wire
Your PT is built as a step up transformer 120vac in 300 vac out so 1:3. one wrap on primary needs 3 wraps on secondary
Resistance should show an "in the park" agreement.
NONE of this description will get you a passing grade in "transformer understanding class 101"
it should get you to; "ok, I'm ready to safely play with deadly voltage to be sure"
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I figured it amount via Amp Garage which is a bit more positive and experience overall than this forum.
It's really rather tedious to explain it all once more and this site in particular is limiting as it's full of ads and doesn't allow you to upload pictures without compressing them to death beforehand
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I figured it amount via Amp Garage which is a bit more positive and experience overall than this forum.
It's really rather tedious to explain it all once more and this site in particular is limiting as it's full of ads and doesn't allow you to upload pictures without compressing them to death beforehand
I have no problem posting pics on this site.
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1.7Meg
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1.7Meg
Nice sunset/sunrise whichever it may be
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:laugh:
the answers in the title
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Red sky at night, sailors delight.
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but tinkering with amps for some time
I'm competent with my knowledge and working abilities
I figured it amount via Amp Garage which is a bit more positive and experience overall than this forum.
It's really rather tedious to explain it all once more and this site in particular is limiting as it's full of ads and doesn't allow you to upload pictures without compressing them to death beforehand
Seriously? Tinkering for some time? Competent in your knowledge and abilities? Nothing about your questions would lead me to believe either one, quite frankly. If the Amp Garage is such a positive experience, why are you here? Didn't that "positive experience" give you real answers? And how do you think folks here feel when they provide info that is not appreciated? I know how it makes me feel. And, by the way, keeping file size down is part of what we all do here to keep this site sustainable. With all due respect... good luck.
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Case in point ^
Folks are quicker to hop on and comment in rudeness rather than in kind.
Ironically, I had to compress the screenshots illustrating the ridiculous file size constraints and the flurry of ads that come with it. I have no problems on TGP, TDPRI, Amp Garage, RigTalk when uploading files. Uploading pictures to a post shouldn't take 10 minutes and 3 different apps. Members aside, this site sucks.
Results of my "tinkering:"
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so you got the PT sorted out n you're up n working?
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Yes
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I figured it amount via Amp Garage which is a bit more positive and experience overall than this forum.
It's really rather tedious to explain it all once more and this site in particular is limiting as it's full of ads and doesn't allow you to upload pictures without compressing them to death beforehand
I'll jump in
We don't tolerate this kind of behavior here.
You need to tone down your hostile behavior or leave.
The moderators have full control on controlling post here and they will take action or I will.
Just be nice and realize that you not being able to post images is your problem, not others.
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ridiculous file size constraints and the flurry of ads
3Meg file size seems very generous. "AdBlock" will take care of the ads.
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I just received an forum alert with this title
The following post, "Re: AnTek Torodial PT wiring" by astronomicum has been reported by GlideOn on a board you moderate:
I read astronomicum's post in reply #16
Looks to me like he laid out facts nicely.
Here's what is going to happen
The other forum members can decide if someone gets to stay or has to leave.
We keep it civil here and any sort of problems get handled quickly.
I would suggest as astronomicum did up above that Amp Garage may be the best place for people if they don't like it here.
I am a member of Amp Garage also and have been for many years.
The nice thing about Amp Garage is that we have many members that belong to both forums
Also, when we get trouble makers or spammers here, I have given a heads up to other amp forums so they know what is going on.
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ridiculous file size constraints and the flurry of ads
3Meg file size seems very generous. "AdBlock" will take care of the ads.
I do not have AdBlock for Chrome on Android unfortunately. Seeing a full page ad each time to post a reply or picture is...irritating.
All, if I have offended anyone clearly that was not my intention.
I felt at the time as if some of the replies were unnecessary, rude and condescending. I feel I have not had the same experience on other forums this far that have been nothing but cordial and inviting.
I am here to learn and gain knowledge from things that aren't written or immediately common sense as I am just one man hungry for not only knowledge but wisdom in using it. It is discouraging to see someone much less myself being belittled for what they do not know.
I see no reason to continue this thread as it has gotten so far off topic, so feel free to delete after the others have a chance to read and hear my reading and case.
Thank you otherwise for your time and assistance.
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I do not have AdBlock for Chrome on Android unfortunately.
You don't need it for Android phones. Read this instead... (https://www.reddit.com/r/chrome/comments/xomm4u/how_do_you_get_rid_of_the_ads_in_chrome_on_an/?onetap_auto=true&one_tap=true)
Scroll down to chacalau's post then to Volknochi's post.