Route 66 said:I have about five degrees Celsius........,
So i will look back and see with my friend before giving up, and send it back. What about the cans???? Are they the good ones?
Route 66 very upset of this hassel.
anatech said:Hi Joe,
I'm pretty sure you've done a good job on it. Way to go!
You're going to be spoiled. Just think what the bulk of the population is listening to!
Hi Daniel,
Keep in mind how old these are. Once you get it running properly you'll be fine. It just will not work perfectly first time out. It's old enough to have a personallity.
-Chris
anatech said:
I think he bought from Audiogon and higher quality is expected there.. but frankly; I dont see how there is anything wrong with this amp based on your information.. It should play ok even with a low bias. If you have major sound issues I'd look at synergy with your other components. There some people who hate the 400a with certain speakers.. thats just the way it goes.
I agree with Anatech.. you buy used you take some chance.. remember; one person's idea of working perfectly is different that anothers..
Hi,
When you turn on an amp with meters you expect them to work, a when its a 9/10 on gon scale its almost pristine to me had least when i sell gears.
Even if its a 1977 dos not mean that i bought scrap, when you ask the seller and deal with him and he says there is no issue whats so ever?
Yo are supposly in trust, its like that in used i have about 94 feedbacks on CAM. and do not sell stock that dos not work properly.
I have a pride to keep my name very good. Dont forget i deal with costumers every days. So when i buy i ask a lot of question before any deal is done even a the last day.
If i would have paid 500$ i would not be here discusion this matter but asking question to how upgrade it to be perfect.Also before i bought it i came here to see de felling about how it was.IMO.(Great) not this one.
So please understand my point of view! I dont think i will keep it.... I dont want the hassel part of upgrading an amp payed this price?$$$
So thanks and i will go and see the first pages of this tread.
regards Route 66
When you turn on an amp with meters you expect them to work, a when its a 9/10 on gon scale its almost pristine to me had least when i sell gears.
Even if its a 1977 dos not mean that i bought scrap, when you ask the seller and deal with him and he says there is no issue whats so ever?
Yo are supposly in trust, its like that in used i have about 94 feedbacks on CAM. and do not sell stock that dos not work properly.
I have a pride to keep my name very good. Dont forget i deal with costumers every days. So when i buy i ask a lot of question before any deal is done even a the last day.
If i would have paid 500$ i would not be here discusion this matter but asking question to how upgrade it to be perfect.Also before i bought it i came here to see de felling about how it was.IMO.(Great) not this one.
So please understand my point of view! I dont think i will keep it.... I dont want the hassel part of upgrading an amp payed this price?$$$
So thanks and i will go and see the first pages of this tread.
regards Route 66
Route 66 said:Hi,
When you turn on an amp with meters you expect them to work, a when its a 9/10 on gon scale its almost pristine to me had least when i sell gears.
Even if its a 1977 dos not mean that i bought scrap, when you ask the seller and deal with him and he says there is no issue whats so ever?
Yo are supposly in trust, its like that in used i have about 94 feedbacks on CAM. and do not sell stock that dos not work properly.
I have a pride to keep my name very good. Dont forget i deal with costumers every days. So when i buy i ask a lot of question before any deal is done even a the last day.
If i would have paid 500$ i would not be here discusion this matter but asking question to how upgrade it to be perfect.Also before i bought it i came here to see de felling about how it was.IMO.(Great) not this one.
So please understand my point of view! I dont think i will keep it.... I dont want the hassel part of upgrading an amp payed this price?$$$
So thanks and i will go and see the first pages of this tread.
regards Route 66
If you want to sell it I am interested... send me a PM..
You can email me at route66atccapcabledotcom, I cannot contact you here , i am still on modération. Also i am not there to sell .
It is a real nice amp in apparence , but i will put you in contact if you want.
Regards Route 66
Edit: Email address modified at request of member - the mod team
It is a real nice amp in apparence , but i will put you in contact if you want.
Regards Route 66
Edit: Email address modified at request of member - the mod team
Looks like I'm up next.
While reading the voltage across an emitter resistor in one of my Stasis 2 amps in order to set the bias, the probe slipped and momentarily grounded the emiter leg against one the output-transistor mounting screws. In addition to the 47 ohm 1/4-watt resistor catching fire on the driver board, I suspect I took out one or more, if not all of the output devices on that channel.
Information from this thread will undoubtedly prove useful as I begin to proceed through troubleshooting and restoration procedures.
Thanks all, and I will let you guys know how it comes along. I have a copy of the schematic, and have been inside more that once, but if it looks like I'm going to get too buried, I start a new thread
While reading the voltage across an emitter resistor in one of my Stasis 2 amps in order to set the bias, the probe slipped and momentarily grounded the emiter leg against one the output-transistor mounting screws.
In addition to the 47 ohm 1/4-watt resistor catching fire on the driver board, I suspect I took out one or more, if not all of the output devices on that channel. Information from this thread will undoubtedly prove useful as I begin to proceed through troubleshooting and restoration procedures.
Thanks all, and I will let you guys know how it comes along. I have a copy of the schematic, and have been inside more that once, but if it looks like I'm going to get too buried, I start a new thread
Hi Forrest,
If even one output is shorted, replace all of them on that channel including drivers. Replace one stage back from your last damaged component. You should match the outputs.
Fresh thermal compound and new insulators go without saying. Try not to over tighten the transistors.
Do not ever use parts from one channel to try in the other. Some guys do this and it is very silly.
-Chris
If even one output is shorted, replace all of them on that channel including drivers. Replace one stage back from your last damaged component. You should match the outputs.
Fresh thermal compound and new insulators go without saying. Try not to over tighten the transistors.
Do not ever use parts from one channel to try in the other. Some guys do this and it is very silly.
-Chris
barchetta said:
As inexpensive as those components are, that's what I figured I would do.
barchetta [/i][b] Did you take out both channels? If not this will be REALLY easy. Just use the good side as reference! [/B][/QUOTE] Thankfully said:
Chris, last night between handing out candy to trick-or-treaters, I managed to lift about ten emitter resistors to in order to test some of the output devices. After finding three that were shorted, I figured I would go with what you and others on this thread recommend and replace them all on that channel as well as the drivers.
Within the next few days, I hope to be making a parts list that will include new mica insulators, compound, small transistors, replacement tantalum caps and select resistors for the driver board, in addition to the output and driver devices, and new emitter resistors. I had recently replaced the small electrolytic with Blackgates, but I have a few extras if needed.
Speaking of emitter resistors, the 1-ohm 5% emitter resistors in this unit that I tested actually measured out between 4 and 6 ohms, so I would guess that those too are past their prime.
Now the big question is what output devices should I order? Presently the amp has "A6" (PNP) and "A8" (NPN) shown on the schematic. As mounted in the unit, most of the A6 Motorola devices are marked 8113 CLASSAA6, another A6 is marked 8205 and another is marked 8039. All of the A8 Motorola devices are marked 8113 STASIS NPN. Recommendations on replacements are a welcome.
Oh yes, I learned long ago not to borrow parts from a perfectly good working electronic anything. I want my working channel to stay working! Also, I recently invested in a pair of IC type clip-on insulated-to-the-tip probs. Hopefully, this should help me not to have another probe mishap in the future.
Thanks!
Sorry I see I said input when I meant output.. just order them all if you can get the same transistors.
Some say they should be matched.. I think the concensus is they should be for the optimum performance.. but I cant tell comparing my repaired unit to my other unit which was professionally repaired..
I have found that the 400a needs to be biased based on season if you live where the temp swings! I biased mine in the winter and when summer came it ran too hot! Glad I know how to do it now.
If you shorted out then all your resistors on your output I bet are bad.. mine were. and you will find maybe 3 transistors bad I bet.
Of course I have no idea what I am talking about really. lol.
Everytime I turn my repaired unit on I have a great feeling of accomplishment!
Some say they should be matched.. I think the concensus is they should be for the optimum performance.. but I cant tell comparing my repaired unit to my other unit which was professionally repaired..
I have found that the 400a needs to be biased based on season if you live where the temp swings! I biased mine in the winter and when summer came it ran too hot! Glad I know how to do it now.
If you shorted out then all your resistors on your output I bet are bad.. mine were. and you will find maybe 3 transistors bad I bet.
Of course I have no idea what I am talking about really. lol.
Everytime I turn my repaired unit on I have a great feeling of accomplishment!
barchetta said:
I think I'm going to need to replace the input devices as well since the resistor that fried was located in the first stage.
Probably won't match them, but will try to buy all of them at once hopefully from the same batch.
New emitter resistors are in the works.
Oh, after all that training you got from this thread, I think you do know what you are talking about.
Also after viewing the following link from a post early in this thread which points to what Nelson recommended as a replacement output device for the 2N5876/78 which is what was originally installed in the Stasis 2:
http://www.diyaudio.com/forums/showthread.php?threadid=34275
I found that Central Semiconductor actually still produces the 2N5876 and 2N5878 (80v, 4Mhz) and are in stock at Mouser:
http://www.centralsemi.com/PDFs/products/2n5875-5878.pdf
EDIT: My bust, Mouser only sells the 2N5878 not the 76.
Hi Forrest,
I would buy components made by On Semi if I were you. Their devices have less of a spread than most other brands. Use something current, like MJ21196 (NPN) and MJ21195 (PNP). The compliments will also be closer together for gain.
To get all the devices from the same batch, you may only be guarantied of that if you buy a rail of 25 for each. Otherwise you may get a mix. So you still need to order extra. You may as well match them too. Consider that you are doing a better job (hopefully) than most repair shops and you are saving a substantial amount of money.
Replace the tantalums with new electrolytic types. You can bypass those with 1 uF film caps. Your amp will sound better for this change. Replace all ceramics with mica or polystyrene types. Again, the highs will be much cleaner. I'll bet you will do this to the other channel after hearing the difference.
-Chris
I would buy components made by On Semi if I were you. Their devices have less of a spread than most other brands. Use something current, like MJ21196 (NPN) and MJ21195 (PNP). The compliments will also be closer together for gain.
To get all the devices from the same batch, you may only be guarantied of that if you buy a rail of 25 for each. Otherwise you may get a mix. So you still need to order extra. You may as well match them too. Consider that you are doing a better job (hopefully) than most repair shops and you are saving a substantial amount of money.
Replace the tantalums with new electrolytic types. You can bypass those with 1 uF film caps. Your amp will sound better for this change. Replace all ceramics with mica or polystyrene types. Again, the highs will be much cleaner. I'll bet you will do this to the other channel after hearing the difference.
-Chris
anatech said:
On Semi it will be. I plan to order extra of everything including enough to re-do the "good" channel in the future. I'm still working on my list for Mouser, but so far, here is what I have for replacements for the outputs, the drivers, and emitter resistors:
Qty. Part # Description
25 MJ15024G ON Semiconductor Transistors Bipolar- Audio TO-3 16A, 250V, 250W NPN
25 MJ15025G ON Semiconductor Transistors Bipolar- Audio TO-3 16A, 250V, 250W PNP
06 MJE15030G ON Semiconductor Transistors Bipolar- Audio TO-220 8A, 150V, 50W NPN
06 MJE15031G ON Semiconductor Transistors Bipolar- Audio TO-220 8A, 150V, 50W PNP
50 CPF31R0000FKE14 Vishay/Dale 3W Flameproof Metal Film Resistors 3watts 1ohms 1%
06 CPF310R000FKE14 Vishay/Dale 3W Flameproof Metal Film Resistors 3watts 10ohms 1%
06 CPF31R5000DKB14 Vishay/Dale 3W Flameproof Metal Film Resistors 3watts 1.5ohms 0.5%
(the following resistor values we not available in Dale
05 283-1.8-RC Xicon 3W 5% Small Metal Oxide Resistors 3watts 1.8ohms 5%
05 283-1.5-RC Xicon 3W 5% Small Metal Oxide Resistors 3watts 1.5ohms 5%
60 4662 Keystone Hardware Mica INSULATOR TO-3
01 120-SA Wakefield Thermal Chemicals SILICON GREASE 4g. - RoHS: COMPLIANT
I'm still working on the remaining devices for the driver board
anatech said:
I'm looking at the small 0.15uF/35v (actual value in the circuit but the schematic shows 50v) and the 4.7uF/25v tantalum caps. At this point I not sure whether to just go back with those or use something else. I couldn't find an electrolytic replacement for 0.15/35v.
Attachments
anatech said:
Aren't all those old Brystons still under warranty?
Anyway, here is my list for the remainder of the devices to be replaced on the driver board:
Qty. Part # Description
06 2N5088G ON Semiconductor Transistors Bipolar- General Purpose TO-92 50mA, 35V, NPN (replaces 6571)
20 MPSA42G ON Semiconductor Transistors Bipolar- General PurposeTO-92 500mA, 300V, NPN (replaces A42)
06 MPSA92G ON Semiconductor Transistors Bipolar- General Purpose TO-92 500mA, 300V, PNP (replaces A92)
06 MPSA56G ON Semiconductor Transistors Bipolar- General Purpose TO-92 500mA, 80V, PNP (replaces 2N4250A)
10 1N914TR Fairchild Diodes - Small SignalDO-35 Hi Conductance Fast
06 1N5404G ON Semiconductor Rectifiers- Standard and Fast Recovery DO-201AD 400V 3A Standard
06 CCF0733R0GKR36 Vishay/Dale 1/4WATT Metal Film Resistors 1/4WATT 33 OHMS 2% Rated to 1/2Watt
06 CCF0747R0GKR36 Vishay/Dale 1/4WATT Metal Film Resistors 1/4WATT 47 OHMS 2% Rated to 1/2Watt
(replaces short damaged resistors)
I'm ordering extras of everything.
Also, I'm still working on figuring out the caps situation. I need to find film caps that will fit the small space where the radial tantalums are now mounted. The leg spacing seems to be a bit too wide on all that I've found of the correct value so far. I'll keep looking . . .
I would just like to say I havent touched this amplifer since I closed it up after its last bias.. in 2007 sometime... still sings.. I even sold my other 400a and kept this one instead as I knew it had all new components in it. Although, I havent fired it up since my last move a few months ago.. but it wasnt dropped.. should be fine.. thanks again all involved in helping me with this repair.. I learned a ton..