Another 200s Amp Question

[emjfox]

Hi all,

New member here and this is my first post. So, go easy on me please.

I just purchased my first Sunn amplifier, a 200s. I have combed through this forum, searched YouTube high and low, and done countless Google searches and I still cannot find a manual or a free catalogue description of the 200s. I have seen schematics, but I do not possess the electrical engineering knowledge to use these.

1. I know the controls are very simple compared to many amplifiers, but I would love to read their intended purposes and any special instructions for all the amps features.
2. I know it is was very likely produced in the late sixties or early seventies, but I want to be able to identify as close to the year as possible.
3. A bonus question, but one I strongly desire to have an answer to, where the heck is there a comprehensive, chronological list or their amps from beginning to at least the 1980s? I was told this forum had one, but I could not locate it.

There is such limited information out there.

Thanks,

June

[Ryan Phelps]

June,
Congrats on your 200S!

1. I've never seen an instruction manual for a 200S. I don't know if they exist.
2. Dating: Early Sunn amps had a sparkly, diagonal weave grille cloth until around 1967 or 1968. Then a rectangular vertical pattern similar to Fender.
You'll sometimes find date stamps inside the chassis. You can also find date codes on the potentiometers.
3.Go to the Q & A line (where you posted) and look at the Sunn Catalog Thread. Not comprehensive, but the best available.

Hopefully LoudThud, EdBass and Soundmasterg will chime in!

[emjfox]

June,
Congrats on your 200S!

1. I've never seen an instruction manual for a 200S. I don't know if they exist.
2. Dating: Early Sunn amps had a sparkly, diagonal weave grille cloth until around 1967 or 1968. Then a rectangular vertical pattern similar to Fender.
You'll sometimes find date stamps inside the chassis. You can also find date codes on the potentiometers.
3.Go to the Q & A line (where you posted) and look at the Sunn Catalog Thread. Not comprehensive, but the best available.

Hopefully LoudThud, EdBass and Soundmasterg will chime in!

Thanks Ryan! And thank you so much for you answers. I had a feeling there weren't manuals haha. I did check out that catalog thread and while it was helpful, it certainly left me with plenty of questions. I will check the amp more thoroughly for dates.

One more question(s). I understand the purpose of a standby switch for warming up an amp for a minute or two, but I find it confusing on this amp as it has the same On/Off positions as the power. Which way should it be when warming up!? Haha. Up with the power or down? Should it be left in either position? I did a search on the forum, but it's odd how little I could find regarding this switch. I know there are strong opinions about these switches in general.

[Soundmasterg]

Thank Ryan! And thank you so much for you answers. I had a feeling there weren't manuals haha. I did check out that catalog thread and while it was helpful, it certainly left me with plenty of questions. I will check the amp more thoroughly for dates.

One more question(s). I understand the purpose of a standby switch for warming up an amp for a minute or two, but I find it confusing on this amp as it has the same On/Off positions as the power. Which way should it be when warming up!? Haha. Up with the power or down? Should it be left in either position? I did a search on the forum, but it's odd how little I could find regarding this switch. I know there are strong opinions about these switches in general.

There used to be a whole bunch of Sunn catalogs and manuals and what not on the old Sunn forum, but they have been gone since the forum got picked up by Tboy/The MEF, probably about 20 years ago now. I'll post what I have saved for the 200S.

For tube amps that use receiving tubes (receiving tubes are what all tube guitar and bass amps use), a standby switch is not required. In some cases depending on how the standby is wired, (Korg-made Vox AC30 reissue for example) it can actually slowly damage the rectifier tube when the standby is used. One of the myths about standby is that it is necessary to stop cathode stripping, which is where the cathode is stripped of the electrons it emits faster than it can emit them, which damages the material the cathode is made of, hence shortening the life of the tube. This is not a concern though with amps that have less than 1500V in them, and even the vaunted Ampeg SVT is only at around 660V. Leo Fender was likely the first to add a standby switch to guitar/bass amps, and it was more of a servicing aid than anything else. In Denmark they actually removed the standby switch from new Fender amps before selling them there back in the day as it didn't meet their regulatory approval and was deemed unsafe.

That said, the way the standby switch functions is that when the amp is in the on mode with the power switch, the standby switch should be in the same orientation for the amp to play....so the top of the switch will be depressed in the on mode. If you want it in standby, then the standby switch should have the bottom depressed. Most people would use the standby this way > turn power on, with standby switch in the standby position, let it warm up for a few minutes, then move standby switch to play position and rock out. You can use it that way, but it is unnecessary.

Greg

[emjfox]

Thank Ryan! And thank you so much for you answers. I had a feeling there weren't manuals haha. I did check out that catalog thread and while it was helpful, it certainly left me with plenty of questions. I will check the amp more thoroughly for dates.

One more question(s). I understand the purpose of a standby switch for warming up an amp for a minute or two, but I find it confusing on this amp as it has the same On/Off positions as the power. Which way should it be when warming up!? Haha. Up with the power or down? Should it be left in either position? I did a search on the forum, but it's odd how little I could find regarding this switch. I know there are strong opinions about these switches in general.

There used to be a whole bunch of Sunn catalogs and manuals and what not on the old Sunn forum, but they have been gone since the forum got picked up by Tboy/The MEF, probably about 20 years ago now. I'll post what I have saved for the 200S.

For tube amps that use receiving tubes (receiving tubes are what all tube guitar and bass amps use), a standby switch is not required. In some cases depending on how the standby is wired, (Korg-made Vox AC30 reissue for example) it can actually slowly damage the rectifier tube when the standby is used. One of the myths about standby is that it is necessary to stop cathode stripping, which is where the cathode is stripped of the electrons it emits faster than it can emit them, which damages the material the cathode is made of, hence shortening the life of the tube. This is not a concern though with amps that have less than 1500V in them, and even the vaunted Ampeg SVT is only at around 660V. Leo Fender was likely the first to add a standby switch to guitar/bass amps, and it was more of a servicing aid than anything else. In Denmark they actually removed the standby switch from new Fender amps before selling them there back in the day as it didn't meet their regulatory approval and was deemed unsafe.

That said, the way the standby switch functions is that when the amp is in the on mode with the power switch, the standby switch should be in the same orientation for the amp to play....so the top of the switch will be depressed in the on mode. If you want it in standby, then the standby switch should have the bottom depressed. Most people would use the standby this way > turn power on, with standby switch in the standby position, let it warm up for a few minutes, then move standby switch to play position and rock out. You can use it that way, but it is unnecessary.

Greg

Greg, I cannot thank you enough for sharing those photos and your knowledge with me! I had heard the switches were most likely unnecessary (similar to the polarity switch now that my amp has a three prong adapter). Any idea the respective years for those catalogue excerpts? I?m assuming the one is 67 as the 100s only has four knobs?

[Soundmasterg]

Greg, I cannot thank you enough for sharing those photos and your knowledge with me! I had heard the switches were most likely unnecessary (similar to the polarity switch now that my amp has a three prong adapter). Any idea the respective years for those catalogue excerpts? I?m assuming the one is 67 as the 100s only has four knobs?

I would assume around 1967 also, but I can't be sure. The old Sunn forum site before MEF had all kinds of manuals and schematics and sales brochures at the top of the page and you could just download anything you wanted, but when the site was going away and Tboy graciously took it over, we all lost that functionality. If Conrad Sundholm (co-founder of Sunn) was still around I could ask him, but he passed earlier this year sadly.

The standby is unnecessary, but it doesn't cause any damage to use it unless you leave the amp on for days sitting in standby possibly. The muting function is useful.

The polarity switch isn't needed with a 3 prong power cord, and hopefully they got rid of the death cap and disconnected the polarity switch. The Sunns were wired up in such a way in the power supply to where if you wire it up the way it should be with the hot wire fused and switched instead of the neutral, on some amps the light in the switch no longer works. If your amp is working well though, I am sure it is fine.

Greg