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fazer

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Makes me think about the demiter pre with an output transformer. (Because of the output tube used). Just a guess.

I wonder if you could use a 1:1 instead of 4:1 transformer, using that output tube as a white follower or some cascode design?
 

pucho812

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makes me wonder what they were thinking. I don't think I ever thought of vacuum tubes and API or decided you know what API needs to do, they need to make vacuum tube gear.
While I do love my vacuum tubes, there is a list of other companies and DIY projects I would go to first before anything from API that has vacuum tubes.
 

pucho812

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I had the same reaction, and then i saw their 400e pedals: Périphériques - Funky Junk
Actually I could see that being useful as it is their solid state tech, just repackaged to work with hi-z instruments. That makes more sense then a vacuum tube for them.

I went through the manual, block diagram shows polarity flip on the output. I was told a couple of years ago from one of Jensen’s head designers that you don’t want to place it there and that it should go on the input.
Their compressor is a solid state compressor with tube output stage. I dunno, I still can’t see this going well for them but then again I can see where console sales have slowed so they trying new things.
 

ruffrecords

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I went through the manual, block diagram shows polarity flip on the output. I was told a couple of years ago from one of Jensen’s head designers that you don’t want to place it there and that it should go on the input.
I heard that too but no explanation as to why was forthcoming. Personally I don't see what the problem is.

Cheers

Ian
 

JohnRoberts

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The "why" is because consumers perceive value from seeing tubes in the audio path.

Last century when I was working as a product manager at Peavey, I refused to do a me-too SKU with a tube in the audio path just for the marketing hook. Frustrated Hartley got another different product manager to do the project (I doubt it is still in production, and don't care).

I am not completely opposed to tubes if done properly. I am still proud of the Peavey/AMR tube mic preamp, and tube limiter/compressor, that didn't suck.

I expect API to have a better chance at marketing tube mojo than Peavey.

JR
 

pucho812

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The "why" is because consumers perceive value from seeing tubes in the audio path.

Last century when I was working as a product manager at Peavey, I refused to do a me-too SKU with a tube in the audio path just for the marketing hook. Frustrated Hartley got another different product manager to do the project (I doubt it is still in production, and don't care).

I am not completely opposed to tubes if done properly. I am still proud of the Peavey/AMR tube mic preamp, and tube limiter/compressor, that didn't suck.

I expect API to have a better chance at marketing tube mojo than Peavey.

JR
This "why" was in reference to the polarity switch after the output transformer. Both Ian and myself have been told it's not a good idea. I heard it from jensen transformers. We both were recommended that we put the polarity switch at the input side.
 

JohnRoberts

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This "why" was in reference to the polarity switch after the output transformer. Both Ian and myself have been told it's not a good idea. I heard it from jensen transformers. We both were recommended that we put the polarity switch at the input side.
I never heard that and there is no logical reason I can think of why it should matter.

It is common practice to locate polarity swaps on mic level inputs as an input function. At an output you are dealing with more current so contact resistance could be an issue.

JR
 

pucho812

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I never heard that and there is no logical reason I can think of why it should matter.

It is common practice to locate polarity swaps on mic level inputs as an input function. At an output you are dealing with more current so contact resistance could be an issue.

JR
that would make the most sense. I will inquire with the Jensen transformer engineer who i spoke with about it and confirm.
 

Winston OBoogie

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This "why" was in reference to the polarity switch after the output transformer. Both Ian and myself have been told it's not a good idea. I heard it from jensen transformers. We both were recommended that we put the polarity switch at the input side.If the output is differential or balanced, then that is the place to put your polarity reverse switch.

I've never put polarity reversal on the input of a mic amp.
My reasoning being, the fewer switch contacts there are at the more vulnerable mic level the better.
The only reason I would do differently is if the output were single ended, but I've yet to build or design a stand-alone mic amp with a single-ended output.

If the output is full differential or transformer balanced, then it makes sense to me to locate your polarity reverse right there.


Obviously, in a typical desk environment where the majority of the internal circuitry isn't differential then I'd opt for putting it on the front in lieu of adding an extra inverter amp.
 

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