http://www.swtpc.com/mholley/PopularElectronics/Oct1971/PE_Oct1971.htm
I found this project and it looks realy easy... no thinking required... I need one like that for a change.
Prolem is, 3 of the transistors are no longer freely available.
So, I would like the silicon gurus out there if there may be alternatives I could use to the following.
schematic : http://www.swtpc.com/mholley/PopularElectronics/Oct1971/PE_Oct_1971_Pg28.jpg
So, I would like the silicon gurus out there if there may be alternatives I could use to the following.
1. SS1122
2. SS1123
3. MPS6566
Thanking you in advance.
I found this project and it looks realy easy... no thinking required... I need one like that for a change.
Prolem is, 3 of the transistors are no longer freely available.
So, I would like the silicon gurus out there if there may be alternatives I could use to the following.
schematic : http://www.swtpc.com/mholley/PopularElectronics/Oct1971/PE_Oct_1971_Pg28.jpg
So, I would like the silicon gurus out there if there may be alternatives I could use to the following.
1. SS1122
2. SS1123
3. MPS6566
Thanking you in advance.
Beautifull to remember...thank you very much Nordic.... alike a treasure to me
You made me very happy with the link you provide.
We can fix here or there to avoid the fire extinguisher...for sure.
Dear Epupa will say to me...as usual:
"Be happy with you basket full of sheet..of papper of course.... and really, this will fill my basket till the top, with sheets of papper previously printed to read with joy!"
hehe
regards,
Carlos
You made me very happy with the link you provide.
We can fix here or there to avoid the fire extinguisher...for sure.
Dear Epupa will say to me...as usual:
"Be happy with you basket full of sheet..of papper of course.... and really, this will fill my basket till the top, with sheets of papper previously printed to read with joy!"
hehe
regards,
Carlos
Nordic...common transistors will work fine there
Q5-BD139C
Q6-BD140C
Q1,Q2,Q4 and Q9- BC546
Q3-BC556
I think they may work fine with those...also the output can be replaced by TIP3055 and TIP2955
I think that voltage amplifier and mirror will need a capacitor from colector to base (Miller)...33J
It is a good idea to include small capacitors into the drivers too..from base to coletor (10J)
From the first transistor base to the feedback one, a series of 100pf and 100 ohms will be nice.
Small capacitor (100N) in parallel with D1
The inclusion of rail resistors (2) of 47 to 100 ohms, and filters also, to input DC voltage.
regards,
Carlos
Q5-BD139C
Q6-BD140C
Q1,Q2,Q4 and Q9- BC546
Q3-BC556
I think they may work fine with those...also the output can be replaced by TIP3055 and TIP2955
I think that voltage amplifier and mirror will need a capacitor from colector to base (Miller)...33J
It is a good idea to include small capacitors into the drivers too..from base to coletor (10J)
From the first transistor base to the feedback one, a series of 100pf and 100 ohms will be nice.
Small capacitor (100N) in parallel with D1
The inclusion of rail resistors (2) of 47 to 100 ohms, and filters also, to input DC voltage.
regards,
Carlos
Attachments
Tiger, Tiger, burning bright
In the forest of the night,
What immortal hand or eye
Could frame thy fearful symmetry?
In what distant deeps or skies
Burnt the fire of thine eyes?
On what wings dare he aspire?
What the hand dare seize the fire?
And what shoulder and what art
Could twist the sinews of thy heart?
And, when thy heart began to beat,
What dread hand and what dread feet?
What the hammer? What the chain?
In what furnace was thy brain?
What the anvil? What dread grasp
Dare its deadly terrors clasp?
When the stars threw down their spears,
And water'd heaven with their tears,
Did He smile His work to see?
Did He who made the lamb make thee?
Tiger, Tiger, burning bright
In the forests of the night,
What immortal hand or eye
Dare frame thy fearful symmetry?
William Blake (1757-1827)
In the forest of the night,
What immortal hand or eye
Could frame thy fearful symmetry?
In what distant deeps or skies
Burnt the fire of thine eyes?
On what wings dare he aspire?
What the hand dare seize the fire?
And what shoulder and what art
Could twist the sinews of thy heart?
And, when thy heart began to beat,
What dread hand and what dread feet?
What the hammer? What the chain?
In what furnace was thy brain?
What the anvil? What dread grasp
Dare its deadly terrors clasp?
When the stars threw down their spears,
And water'd heaven with their tears,
Did He smile His work to see?
Did He who made the lamb make thee?
Tiger, Tiger, burning bright
In the forests of the night,
What immortal hand or eye
Dare frame thy fearful symmetry?
William Blake (1757-1827)
The last paragraph does say it got hot under testing but not during regular listening, also the building instructions have some thermal management instructions.
Thanks Uncle Carlos, I found somme specs for the mps6566, it seems closer to 2n222 except being 10v as opsed to 5.
Oh well those are cheap enough to try a few I guess...
An externally hosted image should be here but it was not working when we last tested it.
Thanks Uncle Carlos, I found somme specs for the mps6566, it seems closer to 2n222 except being 10v as opsed to 5.
Oh well those are cheap enough to try a few I guess...
I am sure that a lot of old folks are happy to see those ancient things
This magazine was nice....you gave an enormous gift to us.
You have made my day Nordic...also Graham Maynard is watching...also John Mateus amd many others.
John told me that was the first amplifier the made in this life.
hehe
thank you,
Carlos
This magazine was nice....you gave an enormous gift to us.
You have made my day Nordic...also Graham Maynard is watching...also John Mateus amd many others.
John told me that was the first amplifier the made in this life.
hehe
thank you,
Carlos
The original tigers were way ahead of there time. but had many problems. Audio Amature did a rebuild of these and talk about many of the problems. like the Bias resistor stack being underated, the use of inferior PECOR brand transistors etc.
Zc
Zc
I have the link for the Universal tiger from 0ct 1970 too, it is mentioned on the first page of the plastic tiger as being 80W (front page of article claims 125W), but I have not read it through yet...
The major diffirence between the two amps, is that the PT uses plastic transistors, and is therefor rated much more conservatively. I do like the mix of solid state and class AB as a "beginner"
http://www.swtpc.com/mholley/PopularElectronics/Oct1970/PE_Oct1970.htm
And the version before that one the super tiger
http://www.swtpc.com/mholley/PopularElectronics/Jul1969/PE_Jul1969.htm
🙂
Hey Carlos its almost christmas...
The major diffirence between the two amps, is that the PT uses plastic transistors, and is therefor rated much more conservatively. I do like the mix of solid state and class AB as a "beginner"
http://www.swtpc.com/mholley/PopularElectronics/Oct1970/PE_Oct1970.htm
And the version before that one the super tiger
http://www.swtpc.com/mholley/PopularElectronics/Jul1969/PE_Jul1969.htm
🙂
Hey Carlos its almost christmas...
My Father built a 20wpc version in 1973 and it always had bad crossover distortion at low volumes. I think raising the bias point would have cured that but i think he said he tried that and it never fully went away with his.
Zc
Zc
The first Tiger from 1967, I built it as a (very) young kid around 1967-68:
What's left of it today, I got tired of rebuilding it and moved on:
An externally hosted image should be here but it was not working when we last tested it.
What's left of it today, I got tired of rebuilding it and moved on:
An externally hosted image should be here but it was not working when we last tested it.
Many thanks for the lin to the thread, I was considering one of the bigger tigers, but I think I will settle for trying the little plastic tiger with some cheap transistors for the educational value...
"Audio Amature did a rebuild of these and talk about many of the problems. like the Bias resistor stack being underated, the use of inferior PECOR brand transistors etc."
Your memory may need to be refreshed.
The Audio Amateur author had problems with the Tigersaurus oscillating BECAUSE he chose to substitute Pecor output devices for Motorola, and the amplifier subsequently blew up.
The voltage divider string for the slave outputs burned up after a period of time on ALL of those type of amplifiers, Dynaco, SAE, GAS, and SWTPC. The only one that I haven't seen burn up was the Heathkit AA1800 (designed by Leach), it had a predriver stage (more current gain), and did not need as much current in the voltage divider.
The first pair I built as a teenager were the 175 mono blocks. Through a wiring error I tried to let the smoke out, but didn't let enough out, as it worked (after I corrected the wiring error).
I always wondered about those people that couldn't get theirs to work. Could they possibly been more inept than me?
I even built a pair from blank boards, populated with ECG outputs no less, and they worked fine.
The first time I had a problem with one was with the newer 60W model with the full comp dual diff front end. It oscillated at 2Mhz after being completed, but only through the AC coupled input. It worked fine through the DC coupled input. The input coupling cap was a tantalum, and the cause of the problem. While the amp cycled the thermal cut-off all day (until I found the problem), it ran hard for several years afterwards driving a 4 ohm load.
SWTPC were not 'shake-the-box' kits (like Dynaco or Hafler), they gave you a bag of parts and a schematic, no fancy step-by-step manuals with photos and drawings (like Heathkit). I shouldn't be surprised so many had problems getting them working. It also helped to have some test equipment, and know how to use it.
The CFP output stage can work and sound fine when done right, I see lots of vintage Marantz and Harman Kardon on eBay all the time. I also see some that blow up (the HK 870 comes to mind).
Your memory may need to be refreshed.
The Audio Amateur author had problems with the Tigersaurus oscillating BECAUSE he chose to substitute Pecor output devices for Motorola, and the amplifier subsequently blew up.
The voltage divider string for the slave outputs burned up after a period of time on ALL of those type of amplifiers, Dynaco, SAE, GAS, and SWTPC. The only one that I haven't seen burn up was the Heathkit AA1800 (designed by Leach), it had a predriver stage (more current gain), and did not need as much current in the voltage divider.
The first pair I built as a teenager were the 175 mono blocks. Through a wiring error I tried to let the smoke out, but didn't let enough out, as it worked (after I corrected the wiring error).
I always wondered about those people that couldn't get theirs to work. Could they possibly been more inept than me?
I even built a pair from blank boards, populated with ECG outputs no less, and they worked fine.
The first time I had a problem with one was with the newer 60W model with the full comp dual diff front end. It oscillated at 2Mhz after being completed, but only through the AC coupled input. It worked fine through the DC coupled input. The input coupling cap was a tantalum, and the cause of the problem. While the amp cycled the thermal cut-off all day (until I found the problem), it ran hard for several years afterwards driving a 4 ohm load.
SWTPC were not 'shake-the-box' kits (like Dynaco or Hafler), they gave you a bag of parts and a schematic, no fancy step-by-step manuals with photos and drawings (like Heathkit). I shouldn't be surprised so many had problems getting them working. It also helped to have some test equipment, and know how to use it.
The CFP output stage can work and sound fine when done right, I see lots of vintage Marantz and Harman Kardon on eBay all the time. I also see some that blow up (the HK 870 comes to mind).
You are my Santa Claus Nordic... regards to Cape town and your family
This thread is my Christmas gift from you.
Thank you...lovely to remember those things.
I am sure many old guys are happy to watch... they do not come with the fear to be considered old...ahahahha..and they are!
regards,
Carlos
This thread is my Christmas gift from you.
Thank you...lovely to remember those things.
I am sure many old guys are happy to watch... they do not come with the fear to be considered old...ahahahha..and they are!
regards,
Carlos
Attachments
The rebuild article in TAA was fun to read:
"I have repaired dozens of blown amps over the years, but never had I witnessed such a scene of cataclysmic destruction. The evidence confirmed the horror stories I had heard: the fiery reputation of Tigersaurus was apparently well earned."
"I have repaired dozens of blown amps over the years, but never had I witnessed such a scene of cataclysmic destruction. The evidence confirmed the horror stories I had heard: the fiery reputation of Tigersaurus was apparently well earned."
Wow, I can't believe the stories about the tigersaurus.
I built 8 of them. 7 came up 100%, never a glitch.
The 8'th one, my friend connected the rails backwards..during powerup, two resistors glowed orange....turned it off, figgered it out, reconnected correctly, then powered up. (the kit had all one color wire)
Four went into service powering a nightclub (disco era, 1978-9). 6 nights a week, 6 hours a night. I never had to repair one over the course of two years or so..
Four I used mobile with 4 K horns.
Historically, only two issues.
R14 sets the front end current sources, it dissipates over spec, wrong part selected..it's a 10K 1/4 watt, it ran hot till it opened.
The zener sets also run hot, they should have better pad designs to draw the heat out the leads.
The 200 ohm dividers are waaaay too hot for the physcial design they used, so I converted to 3ru racks with major airflow channeled over the boards.
That also fixed the output sinks..the orig design was also too hot, I remember cooling the heatsinks with ice cubes during a gig to get the unit back on.
Oh, almost forgot..I turned the bias pot way down..audible notch under a watt, but made it thermally stable as all getout..
Cheers, John
ps..I did forget..back in 86, 87, 88 (memory is foggy), basement flooded...my twin tiger under 14 inches of water.
Dried it for 3 to 4 weeks, opened and cleaned, powered it with a variac..came to life, hasn't failed yet.
I built 8 of them. 7 came up 100%, never a glitch.
The 8'th one, my friend connected the rails backwards..during powerup, two resistors glowed orange....turned it off, figgered it out, reconnected correctly, then powered up. (the kit had all one color wire)
Four went into service powering a nightclub (disco era, 1978-9). 6 nights a week, 6 hours a night. I never had to repair one over the course of two years or so..
Four I used mobile with 4 K horns.
Historically, only two issues.
R14 sets the front end current sources, it dissipates over spec, wrong part selected..it's a 10K 1/4 watt, it ran hot till it opened.
The zener sets also run hot, they should have better pad designs to draw the heat out the leads.
The 200 ohm dividers are waaaay too hot for the physcial design they used, so I converted to 3ru racks with major airflow channeled over the boards.
That also fixed the output sinks..the orig design was also too hot, I remember cooling the heatsinks with ice cubes during a gig to get the unit back on.
Oh, almost forgot..I turned the bias pot way down..audible notch under a watt, but made it thermally stable as all getout..
Cheers, John
ps..I did forget..back in 86, 87, 88 (memory is foggy), basement flooded...my twin tiger under 14 inches of water.
Dried it for 3 to 4 weeks, opened and cleaned, powered it with a variac..came to life, hasn't failed yet.
Every amplifier with leads inverted can burn, but only few guys are not shy to say...
that they already do that.
Others go blaming the amplifier, the designer, the DC voltage, the workbench, the soldering iron, the international sittuation, the temperature, their wives or their dogs.
An exception is Aksa...i made the invertion and nothing happened.
Also, many amplifiers need adjustments, some resistor values need to be changed to reduce off set and to adjust a better class A operation point to class A voltage amplifiers and others adjustments too...and this is normal and common...to assemble and just switch on and go listening is more miracle than reality and happens not so often in real life...with the kits, as exception of course.
Even Kits can produce some problem, reason why many respectable kits producers are prefering, now a days, to construct and to sell their units adjusted...this is made, i suppose, to avoid complains, in special the "blamers"...those ones that never blame themselves.
hehe
Life is beautifull...some guys are a little strange..and this is nice.
regards,
Carlos
that they already do that.
Others go blaming the amplifier, the designer, the DC voltage, the workbench, the soldering iron, the international sittuation, the temperature, their wives or their dogs.
An exception is Aksa...i made the invertion and nothing happened.
Also, many amplifiers need adjustments, some resistor values need to be changed to reduce off set and to adjust a better class A operation point to class A voltage amplifiers and others adjustments too...and this is normal and common...to assemble and just switch on and go listening is more miracle than reality and happens not so often in real life...with the kits, as exception of course.
Even Kits can produce some problem, reason why many respectable kits producers are prefering, now a days, to construct and to sell their units adjusted...this is made, i suppose, to avoid complains, in special the "blamers"...those ones that never blame themselves.
hehe
Life is beautifull...some guys are a little strange..and this is nice.
regards,
Carlos
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