Canuck Audio Mart Hifi and Audio ForumCanuck Audio Mart Hifi and Audio Forum
It is currently Mon Oct 23, 2017 9:12 am

All times are UTC - 8 hours




Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next
Author Message
 Post subject: Marsland 200 amp
PostPosted: Tue Oct 18, 2016 5:57 pm 
Offline

Joined: Thu Sep 25, 2014 4:42 pm
Posts: 216
Location: cambridge, ON, CA
Looking for any info I can get about a Marsland 200 that I recently acquired from a friend. I know little of its history except the company was sold in 1969 and that it was located in Kitchener Waterloo. I would love to get a owners manual/ schematic for this unit. It's currently at a Tech repair in Mississauga as it's not producing any sound, put does power up. It's a nice piece of local history and it's in the original wood case. Any info would be appreciated. Thanks.

G.T.


Attachments:
IMG_7276.JPG
IMG_7276.JPG [ 93.33 KiB | Viewed 1862 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Tue Oct 18, 2016 6:08 pm 
Offline
Premium User
User avatar

Joined: Sat Jul 04, 2009 6:08 pm
Posts: 18449
Location: Montreal, QC, CA
Not much put there on these, but at least you are not the only one looking for info on it. Germanium outputs instead of silicon would make it trickier to repair than most other amps. I had never even heard that Marsland had made home stereo amps until just now, only commercial/pro amps.

http://hifiengine.com/gallery/images/ma ... fier.shtml

http://acrossthedial.ca/index.php/marsl ... amplifier/


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Tue Oct 18, 2016 7:19 pm 
Offline

Joined: Wed Jan 25, 2006 7:39 pm
Posts: 1673
Location: Toronto, ON, CA
Cool!!! Would probably match well with my Marsland Empress 12 speakers!


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Wed Oct 19, 2016 5:00 pm 
Offline

Joined: Thu Sep 25, 2014 4:42 pm
Posts: 216
Location: cambridge, ON, CA
OBI56 wrote:
Not much put there on these, but at least you are not the only one looking for info on it. Germanium outputs instead of silicon would make it trickier to repair than most other amps. I had never even heard that Marsland had made home stereo amps until just now, only commercial/pro amps.

http://hifiengine.com/gallery/images/ma ... fier.shtml

http://acrossthedial.ca/index.php/marsl ... amplifier/




I've been on the 2nd link you provided and on Hifiengine as well, but I could find any info but never thought about miscellaneous. Doesn't seem to be much info out there. I've recapped a few Marantz receivers but I didn't feel confident enough to tackle something like this to be honest.

-- 20 Oct 2016 01:02 --

zhenya01 wrote:
Cool!!! Would probably match well with my Marsland Empress 12 speakers!



The stuff they produced does seem to be fairly rare and Google doesn't seem to provide any info.


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Wed Oct 19, 2016 5:26 pm 
Offline
Premium User
User avatar

Joined: Sat Jul 04, 2009 6:08 pm
Posts: 18449
Location: Montreal, QC, CA
Recapping should not be any more difficult than with more common gear as long as you stay with the same or close to the same spec capacitors as the originals. Same thing with resistor swaps. Its the germanium semiconductors that are the biggest hurdle as most of them have not been made for several decades. Germanium semiconductors are typically 0.2V devices, silicon semiconductors are 0.7V, which implies a substantial re-engineering would be required if ever you needed to substitute newer devices for the older ones. Without schematics, you would be guessing at best.


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Oct 20, 2016 5:48 am 
Offline

Joined: Wed Jan 25, 2006 7:39 pm
Posts: 1673
Location: Toronto, ON, CA
OBI56 wrote:
Recapping should not be any more difficult than with more common gear as long as you stay with the same or close to the same spec capacitors as the originals. Same thing with resistor swaps. Its the germanium semiconductors that are the biggest hurdle as most of them have not been made for several decades. Germanium semiconductors are typically 0.2V devices, silicon semiconductors are 0.7V, which implies a substantial re-engineering would be required if ever you needed to substitute newer devices for the older ones. Without schematics, you would be guessing at best.


Well, here is the problem - 0.2V junction Germanium. You install modern capacitors around them, which have almost no parasitic resistance, and can blow those devices up easily.


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Oct 20, 2016 6:28 am 
Offline
Premium User
User avatar

Joined: Sat Jul 04, 2009 6:08 pm
Posts: 18449
Location: Montreal, QC, CA
zhenya01 wrote:
OBI56 wrote:
Recapping should not be any more difficult than with more common gear as long as you stay with the same or close to the same spec capacitors as the originals. Same thing with resistor swaps. Its the germanium semiconductors that are the biggest hurdle as most of them have not been made for several decades. Germanium semiconductors are typically 0.2V devices, silicon semiconductors are 0.7V, which implies a substantial re-engineering would be required if ever you needed to substitute newer devices for the older ones. Without schematics, you would be guessing at best.


Well, here is the problem - 0.2V junction Germanium. You install modern capacitors around them, which have almost no parasitic resistance, and can blow those devices up easily.


That is why I stated same spec and not same value capacitors. Specs mean far more than just the value in microfarads and rated voltage. Suitable capacitors are still available from industrial suppliers for servicing older military and commercial gear. Typically, technicians who were trained after the very early 70s, have NO idea about how to service germanium device electronics, so I wouldn't allow any tech under the age of 60 even touch one of these because they have no idea what they are doing with stuff like this.


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Oct 20, 2016 7:53 am 
Offline

Joined: Thu Sep 25, 2014 4:42 pm
Posts: 216
Location: cambridge, ON, CA
Well having said that, I'm glad my tech is approaching 70 and has Benin restoring audio for years and he's a great guy to boot. He has it so I will wait to see what he says. Thanks guys.


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Oct 20, 2016 8:09 am 
Offline

Joined: Wed Jan 25, 2006 7:39 pm
Posts: 1673
Location: Toronto, ON, CA
OBI56 wrote:
zhenya01 wrote:
OBI56 wrote:
Recapping should not be any more difficult than with more common gear as long as you stay with the same or close to the same spec capacitors as the originals. Same thing with resistor swaps. Its the germanium semiconductors that are the biggest hurdle as most of them have not been made for several decades. Germanium semiconductors are typically 0.2V devices, silicon semiconductors are 0.7V, which implies a substantial re-engineering would be required if ever you needed to substitute newer devices for the older ones. Without schematics, you would be guessing at best.


Well, here is the problem - 0.2V junction Germanium. You install modern capacitors around them, which have almost no parasitic resistance, and can blow those devices up easily.


That is why I stated same spec and not same value capacitors. Specs mean far more than just the value in microfarads and rated voltage. Suitable capacitors are still available from industrial suppliers for servicing older military and commercial gear. Typically, technicians who were trained after the very early 70s, have NO idea about how to service germanium device electronics, so I wouldn't allow any tech under the age of 60 even touch one of these because they have no idea what they are doing with stuff like this.


Yep. Digikey and Mouser list all parameters on the parts that they sell. Some of the caps specifically come with a few ohms of resistance built-in, which raises a lot of questions from people...


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Wed Mar 29, 2017 12:47 pm 
Offline
User avatar

Joined: Sun Dec 04, 2005 3:16 pm
Posts: 1034
Location: Georgetown, ON, CA
Hi zhenya01,
Quote:
Well, here is the problem - 0.2V junction Germanium. You install modern capacitors around them, which have almost no parasitic resistance, and can blow those devices up easily.

I'm sorry, but that isn't true.

A Marsland amp? Ever cool! I used to deal with Marsland in the later 70's and didn't know they made this product. That was when they were with Leigh Engineering. It would be germanium transistors in that set. I do not expect you would find schematics anywhere in the usual places, but there is an off-chance that a Sams Photofact exists for it. Maybe RCC (like Riders manuals) might have it. You can look some of these up at the Toronto Library as well.

I have some new (old stock) germanium transistors, mostly signal transistors. If your tech needs a part, let me know. If he doesn't complete the repair, I would give it a try as well.

-Chris


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Mar 30, 2017 4:20 pm 
Offline

Joined: Thu Sep 25, 2014 4:42 pm
Posts: 216
Location: cambridge, ON, CA
I got the amp back from my tech and he could not source the germanium transistors. He done the recap on it though, and now I have it home however it's only operating in Mono and not Stereo because of the transistors??? Anyway the right channel is a lower then the left. I tried Deoxit but no inprovement. It's a shame because I really wanted to get this little beauty running to its former glory. If you could help that would be awesome.

GT.


Attachments:
image.jpeg
image.jpeg [ 406.32 KiB | Viewed 1128 times ]
image.jpeg
image.jpeg [ 313.39 KiB | Viewed 1128 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Mar 30, 2017 4:33 pm 
Offline
Premium User
User avatar

Joined: Sat Jul 04, 2009 6:08 pm
Posts: 18449
Location: Montreal, QC, CA
Are those output tubes I see in there?


Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Mar 30, 2017 4:38 pm 
Offline

Joined: Thu Aug 03, 2006 4:43 pm
Posts: 545
Location: Ottawa, ON, CA
Curious... The small transformers look to be driving the output stage, you don't see interstage transformers in solid state gear much, definitely a clue to the age of the design!

-- 30 Mar 2017 19:42 --

OBI56 wrote:
Are those output tubes I see in there?

I don't think so... I think the four output transistors are mounted under the brown fibre transistor sockets.

Those look to me like light bulbs, which I've seen used as bias elements in some designs....

But then I've been wrong before :lol: Dave


Last edited by dcrooks on Thu Mar 30, 2017 4:43 pm, edited 1 time in total.

Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Mar 30, 2017 4:42 pm 
Offline

Joined: Thu Sep 25, 2014 4:42 pm
Posts: 216
Location: cambridge, ON, CA
OBI56 wrote:
Are those output tubes I see in there?


I thought the same at first but my tech says no they aren't. He started to explain what they were but we got side tracked. Just bulbs I believe.

-- 31 Mar 2017 00:45 --

Four outputs underneath the unit.


Attachments:
image.jpeg
image.jpeg [ 379.52 KiB | Viewed 1104 times ]
Top
 Profile  
Reply with quote  
 Post subject: Re: Marsland 200 amp
PostPosted: Thu Mar 30, 2017 8:52 pm 
Offline
User avatar

Joined: Sun Dec 04, 2005 3:16 pm
Posts: 1034
Location: Georgetown, ON, CA
Hi gthomas,
Of course I'll try to help you out.

Transformer coupled output stages were common with germanium output stages. What transistors was he having trouble finding? I'm not kidding, I have a box of brand new signal transistors. I also have a couple TO-3 outputs hanging around here somewhere. It sounds like you need signal transistors. Anyway, I'll do what I can for you.

Best, Chris


Top
 Profile  
Reply with quote  
Display posts from previous:  Sort by  
Post new topic Reply to topic  [ 16 posts ]  Go to page 1, 2  Next

All times are UTC - 8 hours


Who is online

Users browsing this forum: No registered users and 2 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot post attachments in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group