OT:What going to happen if I match 200ohm amp to 16ohm speak

Hello everybody!

This is what I bought several days ago. It looked nice and still look nice ^^. I could find another one which will make a set with this one. And I bought that one too. I didn't have any information about this but , as always, I buy first and check what it is later.

I thought I could match it to my 604 but found later it has 200ohm output impedance.

Now I need extra impedance matching transformer...too bad. And I thought what if I just connect the speaker to the amplifier. What will happen to the amplifier or to the speaker? Just curious.



Telefunken R?hrenverst?rker V 304 / I | eBay



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I am in constant lack of sleep condition because of Altec.
Kim JH

Here is an article you should check out.

Speaker Impedance Explained - Ohms

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Originally Posted by Altec Best

Here is an article you should check out.

Speaker Impedance Explained - Ohms

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Thank you AB.

Does anybody have any idea what this transformer is? This looks like a right matching transformer for 200ohm output amplifier.


Attachment 1300

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Originally Posted by sanhanul

Hello everybody!

This is what I bought several days ago. It looked nice and still look nice ^^. I could find another one which will make a set with this one. And I bought that one too. I didn't have any information about this but , as always, I buy first and check what it is later.

I thought I could match it to my 604 but found later it has 200ohm output impedance.

Now I need extra impedance matching transformer...too bad. And I thought what if I just connect the speaker to the amplifier. What will happen to the amplifier or to the speaker? Just curious.



Telefunken R?hrenverst?rker V 304 / I | eBay



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I am in constant lack of sleep condition because of Altec.
Kim JH

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Yes, you can use it with the 604s as a 1-WATTer. But you have to put a 250mA-Fast Acting-Fuse in the speaker-wiring. The sound quality should be good, as you are almost in a 'constant-current' kind of a situation here.

Actually these 'ohms' things are simply one of the ways to get the full power from the amps. This amp seems to be a 20 watt one. So, at 200 ohms load, it will give 63 volts at 315mA of current. Now this 'current' is the limiting factor as it depends on the gauge-no. of the output winding in the trafo. So 315mA is the highest amount of current which can be drawn. Now a 16 ohms load at 250mA will give 1 watt. The voltage (63volts) is not an issue as it depends on the volume-control setting.

I may be wrong, but to me that looks like a high voltage distribution transformer where the output is then reduced for each speaker & how much maximum power you'd want for each unit. Normaly these are for 70volt systems, but I'll say I've been away from this type of stuff for more than 30 years. I think he's really looking for a transformer to match impedance the same way an "old fashioned" output transformer would work. Is it possible that knowing what the output tubes are it might be possible to find a proper transformer? BTW, I've got a Dynaco Stereo 70 that looks like it was dropped with all the transformers still mounted, so who knows???

Thank you guys for the interest.
Below is another one I have bought. There might be more information about the amplifier. It seems Telefunken V304.
I have never seen this kind of tubes which are on the amps. I think it's going to be hard work to make it sound.
I am reading about impedance matching these days, but in this case,,,It is confusing.



SIEMENS SEV201W R?hrenverst?rker von 1937,perfekt!! | eBay

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Another sleepless night.
Kim JH

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Originally Posted by aditya

Yes, you can use it with the 604s as a 1-WATTer. But you have to put a 250mA-Fast Acting-Fuse in the speaker-wiring. The sound quality should be good, as you are almost in a 'constant-current' kind of a situation here.

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Can you tell me what does it mean '1-WATTer' and the reason why I have to 250mA Fuse? Do you think this amplifier will go well with altec speakers?

Well, if I could only read German. Or whatever language that is.
Any info on this amp in english?
If it really 200 ohm output, it isn't going to work with an 8 ohm speaker. The speaker load is reflected back to the output tube plates and will totally mess the amp up. The amp will think it is powering nearly a dead short.

Best solution here is to get the schematic, then find a diferent output transformer that matches the tube plate Impedance with an 8 or 16 ohm output.

Ron

+1 on what Ron said a 16 ohm load on a 200 ohm amp is not a good thing. DO NOT do it.

Without more info hard to offer solutions.

The transformer in the pic is not a good way to go.

+2 on what Ron & OG said.Yup it will have poor output,poor tone and burn up the amp in short order. I've been seeing these on eBay.Don't know if it could help.I don't have much experience with this particular tube amp.As Ron has said if you have a schematic in English will be able to help you much better.As most of us here are English speaking. That is German and looks like Greek to me. :wink2:.

This might be the right transformer Peerless 15066.. I Don't know enough about that amp though.


Peerless Altec 15066 Transformer 70V 32 Watt Vintage | eBay

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Originally Posted by sanhanul

Can you tell me what does it mean '1-WATTer' and the reason why I have to 250mA Fuse? Do you think this amplifier will go well with altec speakers?

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First I should say that I have sent the wrong answer to you.....I am really sorry.
I was answering to a friend about a similar but SS amp issue, and the copy-n-paste thing has got mixed up.

Actually speaking, tubes, unlike transistors, need a certain amount of load value to function properly. And in your case you have to go for a 200/16 ohms impedance matching transformer.

Actually this might be a good option, and will match just about anything. United Transformer Corp. are very high quality Transformers IMHO.

UTC LS-33 Audio High Level Line Matching Transformer | eBay

Here is another....

http://www.ebay.com/itm/UTC-LS-33-Au...item1c2700be0d

Brain fuzzy, but I am starting to think 200 ohms might be a 25 volt system? I haven't done much in a long time with constant voltage stuff, but a 25v line transformer might do it...

Go here:

EDCOR

EDCOR - EDCOR Support Forum

Ask your question in the forums, you will get a response from people who do transformers daily, not people who stopped 20 years ago like me.

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Originally Posted by Altec Best

Actually this might be a good option, and will match just about anything. United Transformer Corp. are very high quality Transformers IMHO.

UTC LS-33 Audio High Level Line Matching Transformer | eBay

Here is another....

UTC LS-33 Audio High Level Line Matching Transformer | eBay

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Thank you AB. I think this is the right trans for my amplifier. But it looks huge and I don't know how high the price will go up. I will keep that in mind anyway.

Quote:

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Originally Posted by Old Guy

Brain fuzzy, but I am starting to think 200 ohms might be a 25 volt system? I haven't done much in a long time with constant voltage stuff, but a 25v line transformer might do it...

Go here:

EDCOR

EDCOR - EDCOR Support Forum

Ask your question in the forums, you will get a response from people who do transformers daily, not people who stopped 20 years ago like me.

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I will go there and post my question too. Thanks

[/ATTACH]Attachment 1304

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Originally Posted by RonSSS

Well, if I could only read German. Or whatever language that is.
Any info on this amp in english?
If it really 200 ohm output, it isn't going to work with an 8 ohm speaker. The speaker load is reflected back to the output tube plates and will totally mess the amp up. The amp will think it is powering nearly a dead short.

Best solution here is to get the schematic, then find a diferent output transformer that matches the tube plate Impedance with an 8 or 16 ohm output.

Ron

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I found a schematic for the amp. It looks quite simple. I am not sure it contains all the information required for us. (by mistake I post two same schematics. I don't know how to remove one^^)

And below is the information of the AZ5 tube.

AL 5, Tube AL5; R?hre AL 5 ID585, Vacuum Pentode

Quote:

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Originally Posted by Altec Best

As most of us here are English speaking. That is German and looks like Greek to me. :wink2:.

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:biggrin2::biggrin2:

I am using Google translator. This is basically what the seller said about the amplifier.

Siemens 20 watt power amplifier ETS 201 W

Collection of collectible resolution
exellenter condition

original TELEFUNKEN AL5, 100% emission
Valvo AZ12
technically revised (Netzelko changed) and checked
18.35 watts output into 200 ohms
immediately ready for connection
identical to TELEFUNKEN Ela V 304/1, see Radio Catalog 1937/38


SIEMENS vintage power amplifier
near mint condition, best working and sounding condition
tested and serviced technical
AL5 original Telefunken tubes (100%)
Plug and play
shipment / DHL worldwide

Hello sanhanul,

What do you want to know ?

I have also in the mean time downloaded the things that you have done, and have noted the infos. The output trafo in your case is terminated at 200 ohms. So you need a 200/16 ohms matching trafo to connect the 604s. The links that 'AltecBest' has provided are dead spot on. Go for them. The big size is a good thing for trafos, it means good sound.

If you want to know about the quality of these amps, from the design they seem to be old cinema amps, and the 200 ohm thing is for the long cable run from the projection room to the screen area. The sound should be good. The input is also trafo driven.....should be good quality type when they are of such an old era. Someone else may be knowing more about these.

Aditya

Well, someone educate me... The schematic shows 3k to 3.5k impedance? for the primary side of the output transformer. Should the transformer we're looking for be in the same range? It seems to me if your going to use one with a 200 ohm impedance, its looking like way too much of a load. Correct of not? Unless the output transformer is IN the circuit and it just needs a matching transformer.... but when, then, did the 600 ohm become standard?

Quote:

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Originally Posted by sanhanul

Thank you AB. I think this is the right trans for my amplifier. But it looks huge and I don't know how high the price will go up. I will keep that in mind anyway.

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Your Welcome ! They are at $42 and $40 right now.But reserve not met.I think they should sell for around $50-$100.They are not too far from me. Half hour drive.... They are high quality transformers (LS-33).The seller ships to Europe.

Here are a couple of threads on the UTC Transformers at DIY Audio.

http://www.diyaudio.com/forums/tubes...c-ls-33-a.html

Passive preamp with utc transformers - diyAudio

Using the UTC LS-33 as a Push-Pull output for 2A3's - diyAudio

Here is a UTC 1960-1961 catalog. Untitled Normal Page

Data Sheet - http://www.bunkerofdoom.com/xfm/UTC_1970_WEB/023.jpg

@gvasale in post # 17 it says 18.35 watts output into 200 ohms from the google translation.

Just for fun, I dug out my 1970 Cramer catalog. Lots & lots of transformers then. Triad s149a, 3k ohm ct primary, 4, 8, 16 ohm secondarys. UTC HA 135 3k/5k plate, fro 30 to 1.2 ohms in 8 steps. Also Stancor too. Try finding that stuff today. But there is a company that does custom transformers out there. Cant remember the name though.

I don't know about this particular equipment, but many old theatre systems sent the audio signal from the projection booth to the speakers behind the screen at a high impedance to minimize losses in the wires over the long distance. Amplifier power was precious and expensive in the early days. The RCA systems routinely used a 250 ohm tap on the amplifier's output transformer, a passive two way crossover in the rack at 250 ohms, 250 ohm h.f. and l.f. lines out to the speakers, then then autoformers for both h.f. and l.f. set for the particular combination of drivers used in the system. Autoformers like these were used:

http://www.oswaldsmillaudio.com/imag...s/DSC_0691.jpg

RCA 9472-A specs

http://2.bp.blogspot.com/-wMm__DlVvX...s1600/9472.jpg
http://2.bp.blogspot.com/-jKRgPOIlCs...00/xt3083b.jpg

St?phane

A transformer is a transformer, and any of the types will do the job.

The basic difference between an autotransformer and a conventional one is that the autotransformer does not provide that important "isolation" thing between the primary and secondary, as both are part of the same common winding. But as a result of this they also gain in efficiency & cost as the iron-copper requrement & losses reduce by half. Capacitive losses and resonant points also diminish quite a lot.

The OP already has a conventional output trafo built-in to the amp and terminated at 200 ohms. So ideally speaking anymore isolation is unnecessary, and a suitable autotransformer should suffice the needs (if one finds one). But the UTC LS-33 that "AB" has sited is of very good quality also, and will do the job equally well if not more. May be it is a bit costlier compared to a similar but of the autotransformer variety.

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Originally Posted by Steve Schell

Amplifier power was precious and expensive in the early days.

http://www.oswaldsmillaudio.com/imag...s/DSC_0691.jpg

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That is a good point. And This RCA transformer looks sexy :biggrin2: I believe UTC makes very good trans but the shape of UTC trans doesn't really fit to my tasts sometimes^^. And I feel the UTC looks kind of too big for my amplifier
hmm....

Thanks for the information...

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Originally Posted by aditya

Hello sanhanul,

What do you want to know ?

..... and the 200 ohm thing is for the long cable run from the projection room to the screen area. The sound should be good. The input is also trafo driven.....should be good quality type when they are of such an old era. Someone else may be knowing more about these.

Aditya

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I am here to learn. I was very lazy in learning. I would just bring the amplifier to a technician and he will do the job. But the busy and proud technician would not take time to explain everything. Even though he say, I wouldn't understand if I am not ready.
After I meet Altec, I fell in love to it and I decided to learn more about it which I used to do and stopped when I was a kid. And I am learning a lot through friends like you.

Another thing. I want to know whatever options there are for the amplifiers I bought. Because I want to be sure I do the right. I had a very old Philips amplifier with high impedance several years ago. It came to me with separate matching transformers. But the sound was not right.

I don't have any information of the amplifier I bought. But I believe Telefunken had made very very good amplifers in old times. I hope I can see somebody who has successful experience with them.

Thank you for your help.

I still haven't seen a schematic for the whole amp. Do you have one?
It appears to be a single ended pentode output.
If that is the case, you can change the output transformer to one that matches your speakers.
However, the amp may have global feedback and it would need to change if the opt was changed.
Transformers limit bandwidth as it is. Adding an impedance matching transformer at the output of this one is just going to make that worse.

I'm thinking that what you bought "could" work well for HI FI, but it's going to take a lot of work and will be real low powered when done.

Ron

Quote:

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Originally Posted by aditya

Yes, you can use it with the 604s as a 1-WATTer. But you have to put a 250mA-Fast Acting-Fuse in the speaker-wiring. The sound quality should be good, as you are almost in a 'constant-current' kind of a situation here.

Actually these 'ohms' things are simply one of the ways to get the full power from the amps. This amp seems to be a 20 watt one. So, at 200 ohms load, it will give 63 volts at 315mA of current. Now this 'current' is the limiting factor as it depends on the gauge-no. of the output winding in the trafo. So 315mA is the highest amount of current which can be drawn. Now a 16 ohms load at 250mA will give 1 watt. The voltage (63volts) is not an issue as it depends on the volume-control setting.

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Hi, I won this trans. I won them very cheap.^^ I just want to try them just for curiosity.
http://www.ebay.de/itm/ws/eBayISAPI....#ht_500wt_1287

I think I will go for the UTC trans too which AltecBest found .
BTW Will 1 watt be O.K to play my 604B though?

Kim JH

Quote:

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Originally Posted by RonSSS

I still haven't seen a schematic for the whole amp. Do you have one?
It appears to be a single ended pentode output.
If that is the case, you can change the output transformer to one that matches your speakers.
However, the amp may have global feedback and it would need to change if the opt was changed.
Transformers limit bandwidth as it is. Adding an impedance matching transformer at the output of this one is just going to make that worse.

I'm thinking that what you bought "could" work well for HI FI, but it's going to take a lot of work and will be real low powered when done.

Ron

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Hi Ron,
I don't have another schematic except for what I post here.
I thought these amplifier PP output power tubes. What do you mean it appeared to have single ended?

Actually I worried that too many transformers will degrade the sound quality.
It is kind a headache. I am not good at waiting and adjusting to get the best result^^. Hope I can make it sound, and for better, sound nice.

Kim

Quote:

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Originally Posted by sanhanul

Hi, I won this trans. I won them very cheap.^^ I just want to try them just for curiosity.
eBay: Neue und gebrauchte Elektronikartikel, Autos, Kleidung, Sammlerst

I think I will go for the UTC trans too which AltecBest found .
BTW Will 1 watt be O.K to play my 604B though?

Kim JH

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From the picture, it seems the trafo will work, as there are 200ohms & 15ohms taps. So try and see for yourself.

About driving the 604s via 1 watt, yes they are high efficiency drivers, and 1 watt here can give 100db+.
But don't use it with that "250ma-fuse-direct-connection-to-amp" method, as it was the wrong answer sent to you by mistake (as already mentioned in post#11).

schematic here -


Ela V304/1 Amplifier Telefunken Deutschland TFK, build 1938&


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Originally Posted by gvasale

but when, then, did the 600 ohm become standard?

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the original line impedance at the phone company. (in the usa)

That helps, thanks.

Transformer coupled, push pull EL34 output.

If these are phone company amps, bandwidth was likely not hi fi.

Being push pull finding a correct output transformer to match to 8/16 ohm speakers just got real easy.

Ron

I got the UTC transformers. I think I am ready for the amplifier now. Thank you everybody especially AltecBest who found the UTC for me. :)

I learned a lot from this thread and I am encouraged to learn more about the specification of the amplifier and transformer.

I will post the amplifier pictures with the transformers later.

UTC LS-33 Audio High Level Line Matching Transformer | eBay
UTC LS-33 Audio High Level Line Matching Transformer | eBay

Your Welcome ! You snagged them both ? Good Deal !!! The operating Frequency of those Transformers are 10 Hz-40 Khz 20 watts. Even if you don't use them with this amp they are a very good transformer to have in your toolbox... As you can match just about any speaker impedance with those. :Clap:

Good Luck with your project !

Kim, can you give us an update on how it worked out with your amps and the impedance matching?