Calling All "Vintage" Integrated/Receiver Owners
Dec 22, 2023 at 5:18 PM Post #19,066 of 19,093
At last, it arrived, my first Sansui.

I can't believe how good this thing sounds with only 30w of power, even better than my Pioneer Sa 8500; more presence, separation and clarity overall.

I'm searching already for my next Sansui.

_DSC2615 copia.jpg
 
Dec 22, 2023 at 9:30 PM Post #19,067 of 19,093
Go for the alpha series....Very hard to find and no more cheap though ...You already own a very good amp of the AU series...

Anything will be only side grade ... The top Sansui are in the alpha series ...

I own the AU 770 ( retired now ) ....And the alpha 607i...

I use the alpha for my headphone ...Nothing else can beat it i tried ...

by the way merry christmas

Paco ignacio

and congratulation, it is a wonderful amplifier to see ...
 
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Dec 22, 2023 at 10:22 PM Post #19,068 of 19,093
Go for the alpha series....Very hard to find and no more cheap though ...You already own a very good amp of the AU series...

Anything will be only side grade ... The top Sansui are in the alpha series ...

I own the AU 770 ( retired now ) ....And the alpha 607i...

I use the alpha for my headphone ...Nothing else can beat it i tried ...

by the way merry christmas

Paco ignacio

and congratulation, it is a wonderful amplifier to see ...

You picked my interested with the Alpha series, never put much attention to it. I will look more into it.

And merry christmas to you too and everyone else! Thanks!
 
Dec 23, 2023 at 2:21 PM Post #19,070 of 19,093
My fully restored Sansui AU-D707F also sounds better than most headphone amps
That sounds good. I STILL use a Sansui AU-101 I purchased in college around 1974 as a headphone amp, along with a pair of speakers as a second system augmenting a main system providing an ersatz surround sound result. But as a headphone amp, it works every day. I bought some Sansui gear in the ... um ... 1990s I think, and, while it sounded OK, it was nowhere near the look feel, and build quality of my 70s gear. In any case, your headphone amp comment really strikes a familiar chord here. TTmaven
 
Jan 2, 2024 at 12:57 AM Post #19,071 of 19,093
I think I once asked in this thread but I can't seem to find the post.
Has anyone run their headphones off the speaker taps of a vintage tube amp? I've been thinking of running my planars (HE-500, HE-1000, LCD-3) off of the speaker outs of my vintage Scott 299D but I figured I should double check to see if anyone has had any previous issues doing this.
 
Jan 2, 2024 at 11:46 AM Post #19,073 of 19,093
I think I once asked in this thread but I can't seem to find the post.
Has anyone run their headphones off the speaker taps of a vintage tube amp? I've been thinking of running my planars (HE-500, HE-1000, LCD-3) off of the speaker outs of my vintage Scott 299D but I figured I should double check to see if anyone has had any previous issues doing this.
Try contacting this member : @Armaegis. I know he posted about how to listen to headphones off speaker taps, in the past.

In general, if you have the proper adapter cable to go from binding post to balanced headphone jack, you should be fine as long as you are careful with the volume pot.

There are typically two scenarios to be wary of:
1) too much gain/noise, in which case a series resistor on the outputs is typically used to knock down the output
2) it is a transformer couple tube amp, in which case you really want a resistor in parallel on the outputs otherwise there will be a "feedback loop" (not actually, but simpler to explain this way) that could potentially damage or destroy your amp.

If the amp has a headphone jack, chances are it already has one or both of these resistors in place.

Please do not ever use an adapter that goes from binding post to a TRS jack unless you know for sure that the amp has a common ground on the negative legs of the binding posts. Please do not get the robinette box which has been floating around for ages because unless you know what you're doing flipping one switch on that can damage your amp.

If your headphone only has TRS, then I highly recommend updating to a balanced cable. You can always safely use an adapter to convert the headphone cable from 4-pin to 3-pin, but this is not the case for amp adapter cables.

If you want an easy box that converts any amp output to a safe balanced headphone output, this is it: https://store.hifiman.com/index.php/he-adapter.html
It is essentially both the series and parallel resistors mentioned above, forming what is known as an L-pad. Yes you could build one yourself for cheaper if you already have all the tools and knowhow, but the premade box is an ok value.
 
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Jan 2, 2024 at 11:52 AM Post #19,074 of 19,093
In general, if you have the proper adapter cable to go from binding post to balanced headphone jack, you should be fine as long as you are careful with the volume pot.

There are typically two scenarios to be wary of:
1) too much gain/noise, in which case a series resistor on the outputs is typically used to knock down the output
2) it is a transformer couple tube amp, in which case you really want a resistor in parallel on the outputs otherwise there will be a "feedback loop" (not actually, but simpler to explain this way) that could potentially damage or destroy your amp.

If the amp has a headphone jack, chances are it already has one or both of these resistors in place.

Please do not ever use an adapter that goes from binding post to a TRS jack unless you know for sure that the amp has a common ground on the negative legs of the binding posts. Please do not get the robinette box which has been floating around for ages because unless you know what you're doing flipping one switch on that can damage your amp.

If your headphone only has TRS, then I highly recommend updating to a balanced cable. You can always safely use an adapter to convert the headphone cable from 4-pin to 3-pin, but this is not the case for amp adapter cables.

If you want an easy box that converts any amp output to a safe balanced headphone output, this is it: https://store.hifiman.com/index.php/he-adapter.html
It is essentially both the series and parallel resistors mentioned above, forming what is known as an L-pad. Yes you could build one yourself for cheaper if you already have all the tools and knowhow, but the premade box is an ok value.
I knew I recommended the right guy. Thanks Nathan. 👍
 
Jan 2, 2024 at 5:41 PM Post #19,075 of 19,093
My fully restored Sansui AU-D707F also sounds better than most headphone amps I’ve used. Having relay on the outputs is also great for protection. Not a lot of headphone amps have them.
I have been loving my Sansui 7070 with both the 6xx and Atrium. Since I already had it open to recap, I went ahead and replaced the 220 ohm 2 watt cement resistors with some Kiwame 5 watts. Took it up another notch.
IMG_5321.jpeg
 
Jan 2, 2024 at 11:33 PM Post #19,076 of 19,093
In general, if you have the proper adapter cable to go from binding post to balanced headphone jack, you should be fine as long as you are careful with the volume pot.

There are typically two scenarios to be wary of:
1) too much gain/noise, in which case a series resistor on the outputs is typically used to knock down the output
2) it is a transformer couple tube amp, in which case you really want a resistor in parallel on the outputs otherwise there will be a "feedback loop" (not actually, but simpler to explain this way) that could potentially damage or destroy your amp.

If the amp has a headphone jack, chances are it already has one or both of these resistors in place.

Please do not ever use an adapter that goes from binding post to a TRS jack unless you know for sure that the amp has a common ground on the negative legs of the binding posts. Please do not get the robinette box which has been floating around for ages because unless you know what you're doing flipping one switch on that can damage your amp.

If your headphone only has TRS, then I highly recommend updating to a balanced cable. You can always safely use an adapter to convert the headphone cable from 4-pin to 3-pin, but this is not the case for amp adapter cables.

If you want an easy box that converts any amp output to a safe balanced headphone output, this is it: https://store.hifiman.com/index.php/he-adapter.html
It is essentially both the series and parallel resistors mentioned above, forming what is known as an L-pad. Yes you could build one yourself for cheaper if you already have all the tools and knowhow, but the premade box is an ok value.

Thanks, I appreciate your response!
So normally with my solid-state amps I go straight from the speaker taps with a 4-oin XLR and no resistors in between; I would be using the same cable with my 299D I guess I would be best to use an adaptor box like the hifiman?
Also, if I were to use the hifiman box, there probably is no advantage over using the headphone out I already have right?
 
Jan 3, 2024 at 12:10 AM Post #19,077 of 19,093
Ok so I found this image online...
https://www.audioservicemanuals.com/s/Scott/Scott-299D/Scott-299D-Schematic-1.jpg
So it appears that it is a tube amp w/transformer coupled output with different taps for 4/8/16 ohms speakers.

Do you have the manual? Does it say anything about ensuring there is a load attached before turning the amp on?

Hmm looking the schematic it appears the headphone output is taken off before the transformer. One could argue this is actually "better" than after. Fewer things between the signal and your load after all. And with the speaker switch set to "off" then the amp sees a 20ohm resistor parallel'd to ground and a 150ohm resistor in series with the headphone load. So there's already an L-pad built in.

So anyhow, I saw just use the headphone jack and don't worry about the rest. Planar headphones don't really care much about output impedance anyways (flat impedance curves means they will not have affect frequency response; and arguments about damping factor for planars is iffy but that's a rabbit hole to chase on your own).
If you want to use your existing speaker taps to XLR4 adapter, that should be fine. Just make sure the headphone is connected before your flip the switch. Let us know if you can hear a difference between the different taps.
 
Jan 3, 2024 at 12:15 AM Post #19,078 of 19,093
Ok so I found this image online...
https://www.audioservicemanuals.com/s/Scott/Scott-299D/Scott-299D-Schematic-1.jpg
So it appears that it is a tube amp w/transformer coupled output with different taps for 4/8/16 ohms speakers.

Do you have the manual? Does it say anything about ensuring there is a load attached before turning the amp on?

Hmm looking the schematic it appears the headphone output is taken off before the transformer. One could argue this is actually "better" than after. Fewer things between the signal and your load after all. And with the speaker switch set to "off" then the amp sees a 20ohm resistor parallel'd to ground and a 150ohm resistor in series with the headphone load. So there's already an L-pad built in.

So anyhow, I saw just use the headphone jack and don't worry about the rest. Planar headphones don't really care much about output impedance anyways (flat impedance curves means they will not have affect frequency response; and arguments about damping factor for planars is iffy but that's a rabbit hole to chase on your own).
If you want to use your existing speaker taps to XLR4 adapter, that should be fine. Just make sure the headphone is connected before your flip the switch. Let us know if you can hear a difference between the different taps.
Cool, thanks for the little research. I just realized you're in Manitoba so hello from BC!
Not sure what an L-pad is but I'm glad to know that the headphone jack is well-designed.
I don't have the user manual, unfortunately. I might try the speaker taps as an experiment one day just for fun.
 
Jan 3, 2024 at 12:25 AM Post #19,079 of 19,093
An L-pad is just a couple resistors both in series and parallel with the load (either the speaker or the headphone). They are used to trim down the amount of voltage seen by the load and thus reduce volume.

Just a resistor in series will work to reduce it (the mechanism is called a voltage divider). However, often circuits specifically want to see certain loads to operate "optimally", so if you shove resistors into series then the load no longer where you want it. That's where putting a resistor in parallel will kinda kludge it.

On a tube amp, the parallel resistor will typically be on the amp output and the series afterwards in-line with the load. This ensures the amp will mostly only see the load rating of the parallel resistor.

In a crossover, the parallel resistor is typically across the speaker driver, with the series resistor before it. This is because dynamic drivers have varying impedance levels, but a crossover wants to be fixed obviously, so the parallel resistor in this case is to stabilize the apparent load of the driver.
 
Jan 23, 2024 at 5:44 PM Post #19,080 of 19,093
If you have a Sansui xx1 series...you know! My 881 is still my fav receiver.

420489512_10232402021583145_7607257541161761165_n.jpg
 

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