[rubenpp]

Oh I think I'm already there, maybe this is my way of being a bit more sensible ? 

  So I guess it isn't a good buy after all, I was planning to use it for the office   ..Thanks

 

[jaycalgary]

No it is a bit under priced. You have nothing to loose if everything works the way it should in my opinion. I would buy it.

 

[rubenpp]

Thanks jaycalgary

 

[Keithpgdrb]

Quote:

Two normal bias outputs make a lot of sense as this would make it the earliest version of the Mk2 amp.  The basic building blocks are the same though as the later ones but they increased the bias on the outputstage and made some other changes. 
 
Couple of things you could check for me to get a better picture of the circuit, what is written on the transistors.  The TO126 units (squares without heatsinks) are probably all 2SA1156's but I'm not sure what the TO92's are  (half circle ones) and the ones on the heatsinks.  101 and 102 are the input fets so probably J113 or something like that and the other 92's are probably D735 which would make them the bottom of the output stage. 
 
Since the next pot values are +50% then it makes sense to tweak the resistor values instead.  Better yet would be to just replace all the resistors with modern metal films as the amp clearly works as it so the sand is all good.  This would make it essentially new and cost only a few $.  This is what I do with some of these older amps as carbon+moisture is a very bad mix in the long term.  If you can upload a higher resolution version of the same pic then I can pick out the resistor values for you. 

 
I've included higher res pics, I guess if you click on it, you will see the bigger version.  You can zoom in from there.
I dont see anything that starts with a T on the board at all.  I am assuming the transistor parts start with a Q?  I'll give you what I think your asking for.
 
Q209 = B715E  1G3
Q106 = 6 C2611 1 M5
Q111 = B832 OP
Q102 = K117 GR2A
There is also R001 which is hidden behind the 35v cap.  its green, and looks like it says 1.0KΩJ and a 5.  above that it has a triangle and 1W

 

 

 

 

 

 

[NamelessPFG]

Quote:

Would a Stax Lambda Pro with an SRM-T1 MkII amp be good buy at $500 ? Its supposed to be in good shape .

 
Where the heck did you find that deal? I didn't see it on eBay, AudiogoN, or Head-Fi B/S/T.
 
The SRM-T1 often sells for more than $500 by itself, let alone with a pair of headphones to go with it!

 

[John Buchanan]

Quote:

Don't you use them with Lambda pads? This will be my 2nd pair of Sigma pros. I gave up on the first pair a bit quick and sold them. They are in Australia now. I am sure I will keep this pair and looks in better shape. I won't do the 404 mod I'd make a pair from scratch first. I am going to play them on the 717 for now till I get/build better. I have a diy kgsshv in the works but it will certainly be a while as my skill in that area is lacking. You sure have stood behind the Sigma's for a long long time now.

I've got my 2 pairs with the original Sigma pads now on the advice of Birgir, but the Lambda pads also work well. I've got a spare set of the leather 507 pads here, so will try those on one set when the Sigma pads wear out. They will sound excellent on the SRM-717, or an old SRD-7 Pro with a beefy power amp driving them.
My Sigma Pros were $700 about a year ago and in near perfect condition (apart from the perished ear pad netting, which was easily replaced).

 

[Chodi]

I have a question for the Stax insiders. Who actually manufactures the Stax equipment? It certainly can't be Stax as they only have 12 employees. They are, it would seem, a design and engineering firm that subs the manufacturing out. Yes, I realize this is just a guess on my part, but I don't see how 12 people could actually manufacture these products. I am curious as to who actually builds the Stax product?

 

[schorsch]

Quote:

The Sigma Pros came with a brown nextel spray on the stand, compared with the Sigmas, which had a grey Nextel spray.
The Ear pads (including the mesh attached to the ear pads) are still available from, for example, Audiocubes, so a much more cosmetically acceptable effect should be doable. The Sigma series may be a bit underpowered by the SRM-T1, but they are great phones (and the Sigma Pro is very good too - IMHO, it bests the Sigma/404 in a couple of areas too).
Nice price, presuming all is in excellent condition.

Dear John,
I had little listening time with my Sigmas in the last weeks. I tried to make my "new" Sr007 MK2 work with my amps.
The 007 works now with stax talent DA into a pawel hp1 processor (mostly binaural mode) int o my SRM 1MK2PP. Quite a nice combination
BUT yesterday I took on my Sigma and thought WOW There are some aspects which are better than this really high end setup.
 
Regards Georg

 

[spritzer]

All the assembly is done in house but most of the parts are made by others to their specs.  SATO has been their supplier for a long, long time. 
Quote:

 
I've included higher res pics, I guess if you click on it, you will see the bigger version.  You can zoom in from there.
I dont see anything that starts with a T on the board at all.  I am assuming the transistor parts start with a Q?  I'll give you what I think your asking for.
 
Q209 = B715E  1G3
Q106 = 6 C2611 1 M5
Q111 = B832 OP
Q102 = K117 GR2A
There is also R001 which is hidden behind the 35v cap.  its green, and looks like it says 1.0KΩJ and a 5.  above that it has a triangle and 1W
 

 
This amp is very old indeed but the basic layout is pretty much the same as the later ones.m  The 2SA1156 hadn't been released at that point so they used NPN's instead.  Here is the list:
 
001  1K/1W
002  180K  hard to tell from the pic though
003  390K
004  3M3
 
101  910K
102  3K
103  27K
104  270R
105  22K
106  220K  Looks like red-red-yellow but I can't be sure
107  20K
108  270K
109  20K
110  39K
111  39K
112  100K
113  220K
114  3K9
115  39K
116  220K
117  220K
118  1K8  if maroon - silver - red
119  100R
120  100R
121  150K
122  150K
123  150K 
124  150K
125  27K/2W  594-5093NW27K00J
126  27K/2W
127  27K/2W
128  27K/2W
 
All the resistors are 1/2W except where noted.  I like the Vishay CCF for this stuff and they are easy to order.  Just search Mouser with this 71-ccf60 and pick the correct value or the one closest to it from the drop down list. 

 

[Chodi]

Quote:

All the assembly is done in house but most of the parts are made by others to their specs.  SATO has been their supplier for a long, long time. 
 
 
 

So the same 12 people are taking the orders, designing product, doing shipping and receiving, doing repairs, assembling all the products in house and God knows what else? One can only pray that their new owner provides resources to take this operation out of the garage. The products are far too good to be subjected to this limitation. 

 

[Keithpgdrb]

Quote:

All the assembly is done in house but most of the parts are made by others to their specs.  SATO has been their supplier for a long, long time. 
 
This amp is very old indeed but the basic layout is pretty much the same as the later ones.m  The 2SA1156 hadn't been released at that point so they used NPN's instead.  Here is the list:
 
001  1K/1W
002  180K  hard to tell from the pic though
003  390K
004  3M3
 
101  910K
102  3K
103  27K
104  270R
105  22K
106  220K  Looks like red-red-yellow but I can't be sure
107  20K
108  270K
109  20K
110  39K
111  39K
112  100K
113  220K
114  3K9
115  39K
116  220K
117  220K
118  1K8  if maroon - silver - red
119  100R
120  100R
121  150K
122  150K
123  150K 
124  150K
125  27K/2W  594-5093NW27K00J
126  27K/2W
127  27K/2W
128  27K/2W
 
All the resistors are 1/2W except where noted.  I like the Vishay CCF for this stuff and they are easy to order.  Just search Mouser with this 71-ccf60 and pick the correct value or the one closest to it from the drop down list. 

Cant thank you enough for that list spritzer.  few questions though...
1.  when the item description says for example "

1/2watt 390Kohms 1% Rated to 1watt" is it a 1/2 watt, or a 1 watt?  I was trying to find the first resistor 001, which needs to be 1W...​

2.  What is 3M3​

3.  why do some of the resistors end in "R"?  what am I looking for?​

4.  What is a 3K9?  3.9KΩ?​

5.  What is a 1K8?  1.8KΩ?​

 

[Keithpgdrb]

when ordering resistors, is it better to be slightly under, or over the value?

 

[spritzer]

Ahh my Euro teachings muddying the water.  R at the end means ohms so 290R is 290 ohm.  When there is a period we place the multiplier as the period so 3M3 is 3.3M and 2K9 is 2.9K. 
 
Those resistors are 1/2W but they can be uprated by loosening the standards.  I wouldn't use them at 1W so just use something like this:  71-CPF21K0000FKE14
 
Just pick the closest value, doesn't matter which way it is. 

 

[Keithpgdrb]

Quote:

Ahh my Euro teachings muddying the water.  R at the end means ohms so 290R is 290 ohm.  When there is a period we place the multiplier as the period so 3M3 is 3.3M and 2K9 is 2.9K. 
 
Those resistors are 1/2W but they can be uprated by loosening the standards.  I wouldn't use them at 1W so just use something like this:  71-CPF21K0000FKE14
 
Just pick the closest value, doesn't matter which way it is. 

I'm going to take a few minutes to digest what you said here.  I'm sorry, which resistor am I replacing with 71-CPF21K0000FKE14?  You lost me a bit with your last sentence about not using 1W resistors.
 
I can understand that R means Ω.  so I'm good there.  and that a K means a period with a KΩ at the end.  I'll work on that first.

 

[Keithpgdrb]

so 3M3 is a 3.3 Ω resistor right?  Not a KΩ.  and not a Mega Ω.