tommy1000 - False, as you can clearly see in that picture. You mislabeled the transistor's legs. BC182B only comes in the following configuration and always has: Leg1=Collector, Leg2=Base, and Leg3=Emitter.
I don't understand why this is still up for a debate. If you would like to short Collector/Base instead of Emitter/Base, please by all means go ahead an do so. The PCB does not need to be changed. Just rotate the transistor 180 degrees and solder it in backwards. And then possibly watch your project fail.
I don't understand why this is still up for a debate. If you would like to short Collector/Base instead of Emitter/Base, please by all means go ahead an do so. The PCB does not need to be changed. Just rotate the transistor 180 degrees and solder it in backwards. And then possibly watch your project fail.
Looking at the other two transistors in that picture, maybe Goldmund is using MPSA42s. They have the reverse leg configuration. They have used MPSA42s in some of their newer modules. I don't have it on had, so I can't double check. Maybe if they're using the MPSA42s they short the Base/Collector instead of Base/Emitter.
In the original A1 modules, like the ones in the schematic on page one, BC182s Base/Emitter was shorted 100%. I'm holding this module in my hand right now and it's plain as day. I have three different modules for comparison. The transistors are all Motorola.
I would only recommend building this amp like in the original schematic. Of course each and every builder can experiment both ways and post your results. But can we just put this argument to rest? Everyone can build it as they choose. But the original schematic and PCB board labeling should remain the Goldmund way.
In the original A1 modules, like the ones in the schematic on page one, BC182s Base/Emitter was shorted 100%. I'm holding this module in my hand right now and it's plain as day. I have three different modules for comparison. The transistors are all Motorola.
I would only recommend building this amp like in the original schematic. Of course each and every builder can experiment both ways and post your results. But can we just put this argument to rest? Everyone can build it as they choose. But the original schematic and PCB board labeling should remain the Goldmund way.
Those could also be the Goldmund A2 modules. A2 modules did use updated MPSA42 transistors. If anyone builds this amp and uses the newer MPSA42 transistors and shorts the Base/Collector, please CHANGE THE BIAS RESISTOR!
This is mandatory according to Goldmund's service manual. The BIAS resistor R23 (330ohm) should have a 1K to 1K5 resistor soldered in parallel to it. Otherwise the MOSFETS will overheat.
This is mandatory according to Goldmund's service manual. The BIAS resistor R23 (330ohm) should have a 1K to 1K5 resistor soldered in parallel to it. Otherwise the MOSFETS will overheat.
BC182
Thank you for your explanation.
I think that they have used the BC182L instead. The pin configuration fits the board and it has twice as much Ib as the B version, this may explains why they have a lower the valu on R11 to 10k. They have also added a 1u ceramic capacitor across the zener diode in this module. If anyone is interested they can simulate this.
Thank you for your explanation.
I think that they have used the BC182L instead. The pin configuration fits the board and it has twice as much Ib as the B version, this may explains why they have a lower the valu on R11 to 10k. They have also added a 1u ceramic capacitor across the zener diode in this module. If anyone is interested they can simulate this.
Attachments
Power controll board
NagysAudio, I have an other question. The specification for this amp says that is consumes upp to 1000W per channel from the mains. This means that the transformer must be rated at 1000VA. The 9.2 amp is then using 2x500VA transfromers/channel. When connecting such lage transformers to the mains there will be an inrush current on turn on. Can you explain/show how this has been solved in this amp? It would also be interesting to see how the
mains power switching actually works since they are using what seems to be two microswitch puch buttons on the frontpanel to switch the power on and off.
NagysAudio, I have an other question. The specification for this amp says that is consumes upp to 1000W per channel from the mains. This means that the transformer must be rated at 1000VA. The 9.2 amp is then using 2x500VA transfromers/channel. When connecting such lage transformers to the mains there will be an inrush current on turn on. Can you explain/show how this has been solved in this amp? It would also be interesting to see how the
mains power switching actually works since they are using what seems to be two microswitch puch buttons on the frontpanel to switch the power on and off.
This would make sense and tie in with the fact that it's totally pointless to short base to emitter, but to short base to collector makes a useful temperature sensing diode.
The correct transformer size is critical for a good sounding amp. You definitely don't want to under specify here.
Based on the 1000W spec I would use 2kVA per channel (or 2 x 1kVA per channel).
Can anyone confirm what goldmund use here?
Based on the 1000W spec I would use 2kVA per channel (or 2 x 1kVA per channel).
Can anyone confirm what goldmund use here?
Hi Nagys,
For the relay, both PA and TMP can be use, right? The TMP just make it more easier to connect.
Hi Alex,
I tried to measure your 10000uf and they are 30mm in diameter but what I find locally are 35mm's. As I renew the PCB I will move it a bit to fit the 35mm. You are so fast and I had almost the same modification as you do but still trying to tidy up the stuff while you had them finished and posted already. I had the fuses at the vertical edge of the board instead and the +80v seperate from the other 2. but I will follow yours on the new move.
For the relay, both PA and TMP can be use, right? The TMP just make it more easier to connect.
Hi Alex,
I tried to measure your 10000uf and they are 30mm in diameter but what I find locally are 35mm's. As I renew the PCB I will move it a bit to fit the 35mm. You are so fast and I had almost the same modification as you do but still trying to tidy up the stuff while you had them finished and posted already. I had the fuses at the vertical edge of the board instead and the +80v seperate from the other 2. but I will follow yours on the new move.
Bigpanda - Yes, both PA and TMP can be used, they have the same pin/leg layout. The TMP has a slightly bigger body, so if both options are to be offered, please make sure that it will physically have enough room. But again, the circuit board traces, leg/pin configuration will be identical.
Also, distributors like Newark and Mouser only stock the PA version. Since that one is easier to find, I'm guessing most people will use the PA version, even though TMP is easier to connect.
Also, distributors like Newark and Mouser only stock the PA version. Since that one is easier to find, I'm guessing most people will use the PA version, even though TMP is easier to connect.
Jacco Vermeulen - Do you post just to post? A lot of the time your posts make virtually no sense...
Goldmund Mimesis 3 and 6 are both 80-100 watt amplifiers. They both used the now obsolete Panasonic S4-24V relay (4 amp).
Goldmund Mimesis 9.2, the one we are all building and the one that I posted the schematic from on page one, is a 250+ watt amplifier. It needs at least an 8 amp relay.
The original relay that Goldmund used was a Panasonic JNT1A-TMP-DC24V (30 amp). This relay is no longer available.
The current replacement relays from Panasonic are: JTN1S-PA-F-DC24V (30 amp) and JTN1S-TMP-F-DC24V (30 amp).
These are the relays that the protection circuit will be modeled on. They are identical to the original Goldmund Mimesis 9.2 relay.
Goldmund Mimesis 3 and 6 are both 80-100 watt amplifiers. They both used the now obsolete Panasonic S4-24V relay (4 amp).
Goldmund Mimesis 9.2, the one we are all building and the one that I posted the schematic from on page one, is a 250+ watt amplifier. It needs at least an 8 amp relay.
The original relay that Goldmund used was a Panasonic JNT1A-TMP-DC24V (30 amp). This relay is no longer available.
The current replacement relays from Panasonic are: JTN1S-PA-F-DC24V (30 amp) and JTN1S-TMP-F-DC24V (30 amp).
These are the relays that the protection circuit will be modeled on. They are identical to the original Goldmund Mimesis 9.2 relay.
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The S4 relay is an SDS original, later on SDS joined up with Matsushita and it became the SDS-Matsushita S4 series.
Ah, but for the American market it became the Aromat S4 relay.
And then the poor thing got a Panasonic label.
Read the datasheet, it's 5 Amps continuous, per contact.
Ah, but the S4 has 4 contacts, that makes it a 20Amp continuous relay.
Ah, but there is more.
The NT1 is an SDS relay as well.
The SDS-Matsushita NT1, Aromat, Panasonic, blah blah blah.
Look, and Ye shall find originals, for less.
Unused gas-filled relays don't age, you know.
Maybe because you don't listen too well.
I have the same problem, i'm trying to figure why you've been peddling this amp on the forum for the last 3 years.
Never mind.
(btw : the dual toroid thing with a transformer for each rail is what Goldmund peep-holed from Dieter Burmester, the 850 monaural model from 1985.)
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Nagys,
...............it's not nice to mess with jacco, you will usually get burned, as you just found out.......😀
He has a vast amount of knowledge about such matters.
Jam
...............it's not nice to mess with jacco, you will usually get burned, as you just found out.......😀
He has a vast amount of knowledge about such matters.
Jam
Attachments
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Jacco - Again, you make very little sense. The original Goldmund Mimesis 9.2, the one we are building, had a JNT1A-TMP-DC24V relay. This relay is no longer available. The replacements that are currently available are: JTN1S-PA-F-DC24V and JTN1S-TMP-F-DC24V. They're identical in every way. They're also available from every big electronic distributor (Newark, Mouser, etc.) for under $4. Why would I need to hunt for the obsolete S4-24V relay that the Mimesis 9.2 DID NOT USE? Is this logical? And even if I did want to use the S4-24V for some illogical reason, where could I get it for under $4?
Me getting burned? I definitely think not.
Me getting burned? I definitely think not.
As far as the toroidal transformers are concerned... Goldmund Mimesis 9.2 (mono block) used 2 transformers. One to feed the + rail voltage and one to feed the - rail voltage. Maximum power that the amp draws is 400 watts at 3 ohms. So... Each transformer should be rated at 400 watts X 1.4 = 560 watts. If one is to use just a single transformer to feed both +/- rails, you will need a 560 watt toroidal transformer. If 2 transformers are used, then each should be rated at 280 watts.
I personally like Hammond transformers: Hammond Mfg. - Toroid Power Transformer - (182 Series)
Take a loot at:
182L60 (300 watts) $95
182P60 (625 watts) $135
I personally like Hammond transformers: Hammond Mfg. - Toroid Power Transformer - (182 Series)
Take a loot at:
182L60 (300 watts) $95
182P60 (625 watts) $135
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Explain where does the formula for 400 watt x 1.4 = 560 watt come from. Is this standard engineering practice? I assume that you suggest 4 x 560 watt(?) transformers.
tommy1000 - The way that Goldmund Mimesis 9.2's switching works is like this... You have to press both buttons at the same time for the amp to turn on. There's a tiny circuit board on the front panel where the switches are located. I have no idea what else is on that circuit board. I don't have this amplifier to take a look at. But as soon as both buttons are pressed, the amp turns on.
My Goldmund Mimesis 6 just simply turns on by flipping a toggle switch. Nothing fancy.
Goldmund Mimesis 3 also has 2 buttons on the front panel. You have to press them both at the same time for the amplifier to turn on. In addition, it also has a delayed turn on. After one presses both buttons, it takes almost 3 minutes before the amplifier actually turns on and the relays engage the speaker outputs. Mimesis 3 has a circuit board on the front panel and also one on the rear panel. The turn on circuit has more parts than the entire schematic for the amplifier itself!
Mimesis 3 also has an extremely complicated protection circuit and power supply with dozens of smaller value paralleled capacitors, and 4 toroidal transformers. In addition, it has two A1 modules per channel (one of them solely to be able to switch phase). All in all, it probably has more than 1000 parts, all crammed into a chassis of only 1.75" in height. Every single part of this chassis is made out of machined aluminum (no sheet metal). This amplifier is an extraordinary piece of engineering. And would be a nightmare to clone!
My Goldmund Mimesis 6 just simply turns on by flipping a toggle switch. Nothing fancy.
Goldmund Mimesis 3 also has 2 buttons on the front panel. You have to press them both at the same time for the amplifier to turn on. In addition, it also has a delayed turn on. After one presses both buttons, it takes almost 3 minutes before the amplifier actually turns on and the relays engage the speaker outputs. Mimesis 3 has a circuit board on the front panel and also one on the rear panel. The turn on circuit has more parts than the entire schematic for the amplifier itself!
Mimesis 3 also has an extremely complicated protection circuit and power supply with dozens of smaller value paralleled capacitors, and 4 toroidal transformers. In addition, it has two A1 modules per channel (one of them solely to be able to switch phase). All in all, it probably has more than 1000 parts, all crammed into a chassis of only 1.75" in height. Every single part of this chassis is made out of machined aluminum (no sheet metal). This amplifier is an extraordinary piece of engineering. And would be a nightmare to clone!
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What headroom is needed with a transformer? Could it be possible that you referring to the efficiency and heat losses related to the amp? This is a completely new discovery for me and I have been an engineer for 40 years.
There are members here wants to learn things on this web and just throwing numbers of the top of your head cannot be helpful to them.
Does the Goldmund use 560VA transformers, you have one in front of you, why not look.