John, I’m trying to figure out IF I’ll be able to start with your design anyway. I would like to have the component values. As I can ask you about my tricky (and stupid) questions and problems that may (will) arise I find this point very important in succeeding in this kind of project.
I have a lot of questions, some of them may seem very basic. In that case, I hope you accept.
- What is MT1+MT2+MT3 and where do I connect MT- Is this for the power supply?
- In your schedule you write 300B but in the text you mention that you use VV32B “...Other than anode dissipation, there are a number of significant differences between the VV32B and the 300B: One is the minimum grid leak value....” Is the other component values for the use of 300B?
- Where do I connect –200V? Or is this just a reference point for voltage measuring that should be 200V? And in that case where do I put the other pole for measure?
- Where do I connect GND (ground)? I understand this is a very important point.
- The “unfinished” lines to the left of R107 and to the right of R108 is that just “dead ends”.
- What do I use RV 151 and RV152 for? Moving coil meters to see if there is any dangerous current in V102 and V103 or just outputsignal?
- Can the V102 be EL 84 or EL 86?
- “...The power supply is still in a preliminary stage. I am working on a regulated power supply at present....” Is the power supply design finished? What is the cost about for the transformer? Did you have it custom made?
- I have heared that some transformers should be separated from the rest of the construction to avoid inteference (buzz sound etc). Is that the case in this design?
- What kind of high voltage (is it 500V?) cable should I use? Are there any connections in your schematic that should not use this cable?
I have more questions, but I guess this is more than enough today!
Per
I have a lot of questions, some of them may seem very basic. In that case, I hope you accept.
- What is MT1+MT2+MT3 and where do I connect MT- Is this for the power supply?
- In your schedule you write 300B but in the text you mention that you use VV32B “...Other than anode dissipation, there are a number of significant differences between the VV32B and the 300B: One is the minimum grid leak value....” Is the other component values for the use of 300B?
- Where do I connect –200V? Or is this just a reference point for voltage measuring that should be 200V? And in that case where do I put the other pole for measure?
- Where do I connect GND (ground)? I understand this is a very important point.
- The “unfinished” lines to the left of R107 and to the right of R108 is that just “dead ends”.
- What do I use RV 151 and RV152 for? Moving coil meters to see if there is any dangerous current in V102 and V103 or just outputsignal?
- Can the V102 be EL 84 or EL 86?
- “...The power supply is still in a preliminary stage. I am working on a regulated power supply at present....” Is the power supply design finished? What is the cost about for the transformer? Did you have it custom made?
- I have heared that some transformers should be separated from the rest of the construction to avoid inteference (buzz sound etc). Is that the case in this design?
- What kind of high voltage (is it 500V?) cable should I use? Are there any connections in your schematic that should not use this cable?
I have more questions, but I guess this is more than enough today!
Per
Per, I have exactly the same issue with the Lundahl trans' aesthetics. I mount mine below the top plate usually, but in one of the designs I'm working on, I've ordered some die-cast aluminium enclosures from RS. They usually need little finishing, ie the castings are good and quite free of moulding flash and dags, but they're easy to sand smooth anyway. Then polish, anodise, powdercoat, electroplate or paint. The size for the largest LL1620 trans cost abour $US12 ea with a flanged mounting lid. These are common enough so you'll proboly be able to find a supplier locally too.perka said:
Brett said:
Brett, who are RS?
Anyway I got the quotation from Lundahl transformers for the
"300B PSE MK2 - Parallel Single Ended" by Andrea Ciuffoli which was about the same price as for the Italian market.
If I go for Johns 845 I will ask Lundahl (and John) if they have any suitable transformers for this project.
They do have an output transformer that is called LL1620 with 11.5Kohm, 80mA, 45H and the question is if I can substitute it for the specified 10Kohm, 70mA?
And for the driver (interstage) (is this the grid choke?) Lundahl don't seem to have anything close to the specified 50mA, 5Kohm, 1:1, 30-50H, C-core
Do somebody have a hint where to find this?
per
OnRyoku amplifier
Hi Per,
I'm very happy to help you all I can whichever design you chose.
And, I feel honoured that you are considering my own.
But I do have more responsibility for my own design, especially to ensure safety. I'm a little concerned whether you have the necessary experience with such high voltages.
I am prepared to help, as long as you can convince me that you appreciate the level of care required in ensuring the safety of yourself, and others around you.
This sounds terribly patronising- and I'm relly sorry for that, but this can be a very dangerous project. It would be a tragedy if something intended to give pleasure, ended up by causing death.
The supply rails are:
+1250 volts for the output stage
+500 volts for the driver stage
+550 volts for the input mu-stage
-200 volts for bias
Plus the valve heaters.
May I ask, why you think OnRyoku is better than the 300B PSE projects you were thinking of?
Some general notes on my schematic:
http://www.dhaen.org.uk/vdocs/845.gif
This is only the signal part of the amplifier. The power supply, even in it's earliest unregulated form, was more complex.
In the UK it is customary to use the terms HT to signify High Tension(voltage) instead of the American +B(battery) nomenclature. So those MT1+, MT2+ are actually meant to be HT1+, HT2+ but my graphics capture was not good.
The paricular schematic posted is the one that I have extended to have a balanced input. If you do not require a balanced input, I suggest you use a standard mu-stage. This will reduce the power supply complexity.
The top valve in the mu-stage can be EL84 or EL86.
I will tell you about the transformers spec's and how to get them presently.
You asked about the separation of transformers to avoid interaction: This is the case. For my own amp, I have not chosen monoblock construction, but 2 blocks; 1 contains the power supply, the other contains both amplifier channels.
If you decide to build monoblocks, I suggest that you "breadboard" one channel, and experiment with positioning.
Please understand that I can only give general guidance about the physical construction. No understandable mechanical drawings exist. I can photograph mine if you are interested.
If you need detailsed construction drawings; may I suggest that you consider Andrea Ciuffoli’s design instead of mine.http://www.audiodesignguide.com/my/845se.html
Cheers,
Hi Per,
I'm very happy to help you all I can whichever design you chose.
And, I feel honoured that you are considering my own.
But I do have more responsibility for my own design, especially to ensure safety. I'm a little concerned whether you have the necessary experience with such high voltages.
I am prepared to help, as long as you can convince me that you appreciate the level of care required in ensuring the safety of yourself, and others around you.
This sounds terribly patronising- and I'm relly sorry for that, but this can be a very dangerous project. It would be a tragedy if something intended to give pleasure, ended up by causing death.
The supply rails are:
+1250 volts for the output stage
+500 volts for the driver stage
+550 volts for the input mu-stage
-200 volts for bias
Plus the valve heaters.
May I ask, why you think OnRyoku is better than the 300B PSE projects you were thinking of?
Some general notes on my schematic:
http://www.dhaen.org.uk/vdocs/845.gif
This is only the signal part of the amplifier. The power supply, even in it's earliest unregulated form, was more complex.
In the UK it is customary to use the terms HT to signify High Tension(voltage) instead of the American +B(battery) nomenclature. So those MT1+, MT2+ are actually meant to be HT1+, HT2+ but my graphics capture was not good.
The paricular schematic posted is the one that I have extended to have a balanced input. If you do not require a balanced input, I suggest you use a standard mu-stage. This will reduce the power supply complexity.
The top valve in the mu-stage can be EL84 or EL86.
I will tell you about the transformers spec's and how to get them presently.
You asked about the separation of transformers to avoid interaction: This is the case. For my own amp, I have not chosen monoblock construction, but 2 blocks; 1 contains the power supply, the other contains both amplifier channels.
If you decide to build monoblocks, I suggest that you "breadboard" one channel, and experiment with positioning.
Please understand that I can only give general guidance about the physical construction. No understandable mechanical drawings exist. I can photograph mine if you are interested.
If you need detailsed construction drawings; may I suggest that you consider Andrea Ciuffoli’s design instead of mine.http://www.audiodesignguide.com/my/845se.html
Cheers,
Per,
I just noticed your questions about Lundahl transformers.
I did consider using Lundals. Look at the paragraph:
"The search for Iron":
http://www.dhaen.org.uk/vdocs/onryoku.htm
Lundahls could make a fine amplifier indeed. But it would be a different amplifier - like Ciuffoli’s.
IMO The transformers are the "essence".
Cheers,
I just noticed your questions about Lundahl transformers.
I did consider using Lundals. Look at the paragraph:
"The search for Iron":
http://www.dhaen.org.uk/vdocs/onryoku.htm
Lundahls could make a fine amplifier indeed. But it would be a different amplifier - like Ciuffoli’s.
IMO The transformers are the "essence".
Cheers,
John,
The safety matters is the most important. And I wouldn’t try anything without asking how to do it first.
If I don’t have the knowledge, I won’t “try”.
First of all I must mention all the reasons to chose your design.
-Your knowledge seems to be as good as your helpfulness to other members in this forum. I have read a lot of other threads and you seem to live up to this all the time.
-I have heard so much good about the Cary 805 matching with my proacs so a similar design is more likely to be a good match than trying something else.
-I use 30W with EL34 today, which is enough power for my proacs. I just want to try construction with more quality power. Your design corresponds to this power requirement, which the PSE with 300B do not.
“...Please understand that I can only give general guidance about the physical construction. No understandable mechanical drawings exist. I can photograph mine if you are interested...” Mechanical drawing? If you mean how big wholes I must make and the “design”, of course this is of minor importance and more a creative problem.
OK, I get your point about the transformers. They must be custom made to suit the unique specifications. BTW, how much is the total cost for those transformers (about)?
I have a balanced output from my cd, but to simplify things I can use the normal out instead. What will the difference in your schematic be?
Is the minus of the input signal directly connected to the minus of the output signal?
I choose to have one box for the power supply and another for both channels.
I have looked a on the page with the Italian 845 and have learned even more from that construction which seems to be of the same principle as yours except for all the components above 6SN7.
Of course, It would be nice to see a picture of your amplifier!
Per
The safety matters is the most important. And I wouldn’t try anything without asking how to do it first.
If I don’t have the knowledge, I won’t “try”.
First of all I must mention all the reasons to chose your design.
-Your knowledge seems to be as good as your helpfulness to other members in this forum. I have read a lot of other threads and you seem to live up to this all the time.
-I have heard so much good about the Cary 805 matching with my proacs so a similar design is more likely to be a good match than trying something else.
-I use 30W with EL34 today, which is enough power for my proacs. I just want to try construction with more quality power. Your design corresponds to this power requirement, which the PSE with 300B do not.
“...Please understand that I can only give general guidance about the physical construction. No understandable mechanical drawings exist. I can photograph mine if you are interested...” Mechanical drawing? If you mean how big wholes I must make and the “design”, of course this is of minor importance and more a creative problem.
OK, I get your point about the transformers. They must be custom made to suit the unique specifications. BTW, how much is the total cost for those transformers (about)?
I have a balanced output from my cd, but to simplify things I can use the normal out instead. What will the difference in your schematic be?
Is the minus of the input signal directly connected to the minus of the output signal?
I choose to have one box for the power supply and another for both channels.
I have looked a on the page with the Italian 845 and have learned even more from that construction which seems to be of the same principle as yours except for all the components above 6SN7.
Of course, It would be nice to see a picture of your amplifier!
Per
OnRyoku 845SE amp
Hi Per,
Safety:
I'm glad you appreciate the importance, let's keep that at the top of our "stack".
Thank you for your kind words.
I'm afraid I know nothing of your speakers, so cannot comment on the exact drive requirements. Presumably your own research has led you to your decision.
Actually, the pysical construction is as important as the electronic design, in terms safety and performance.
Once you are conversant with all the components required, you will find it can be a "mind twister" to decide how to lay everything out. Sometimes compromises must be made. Deciding which compromise can be difficult.
The transformers came from Automatic Electric Europe.
The page with the output transformers on is:
http://www.ae-europe.nl/uitgangstrafo.htm
As you can see the current price for the type of output transformer I used is 462,20 Euro (per pair) including tax. You should not have to pay the BTW (tax).
This is incredibly cheap for an amorphous C-core transformer. I think he will "pot" it for the same price too.
The driver transformers were much cheaper. The owner of AE, Wil Blaauw, does not "like" driver transformers, but is happy to make them for his customers. I don't have the exact price with me today, but I think they were less than 150 Euro for the pair. That's brilliant pricing!
Please do not think that because these prices are below his competitors prices, that his transformers are built cheaply. In fact everyone who has used them has been more than satisfied. I can supply a list of users if you are intersted. They are mainly Dutch DIYers.
Balanced vs. unbalanced:
The amplifier, as designed, is not an integrated amplifier. It has no source selection or volume control.
However, the input sensitivity (I don't have the figure on me) is such that these could be done passively.
So, you could either build in a switched source selsctor and volume control, or, build a "passive preamp".
There is hardly any difference in the amp complexity between balanced and unbalanced. But there is in the power supply. There are 2 extra stabilized voltage rails required.
When choosing between balanced and unbalanced, you musy consider complications to the volume control. Either you must use a 4 gang control, or a tapped transformer, or convert to unbalanced - just for the volume control.
There is a lot to think about. You should think hollistically.
Similarities:
Yes there are some similarities between mine and Ciuffoli’s.
In fact, you might consider that as you are going to use a 300B rather than a VV32, you might get away with his input stage. I don't know if that would work for sure. There are many variables.
There is no problem using a 300B with my design.
A VV32B would not work in his design.
As soon as I can get my digital camera back, I'll send you a snapshot.
Cheers,
Hi Per,
Safety:
I'm glad you appreciate the importance, let's keep that at the top of our "stack".
Thank you for your kind words.
I'm afraid I know nothing of your speakers, so cannot comment on the exact drive requirements. Presumably your own research has led you to your decision.
Actually, the pysical construction is as important as the electronic design, in terms safety and performance.
Once you are conversant with all the components required, you will find it can be a "mind twister" to decide how to lay everything out. Sometimes compromises must be made. Deciding which compromise can be difficult.
The transformers came from Automatic Electric Europe.
The page with the output transformers on is:
http://www.ae-europe.nl/uitgangstrafo.htm
As you can see the current price for the type of output transformer I used is 462,20 Euro (per pair) including tax. You should not have to pay the BTW (tax).
This is incredibly cheap for an amorphous C-core transformer. I think he will "pot" it for the same price too.
The driver transformers were much cheaper. The owner of AE, Wil Blaauw, does not "like" driver transformers, but is happy to make them for his customers. I don't have the exact price with me today, but I think they were less than 150 Euro for the pair. That's brilliant pricing!
Please do not think that because these prices are below his competitors prices, that his transformers are built cheaply. In fact everyone who has used them has been more than satisfied. I can supply a list of users if you are intersted. They are mainly Dutch DIYers.
Balanced vs. unbalanced:
The amplifier, as designed, is not an integrated amplifier. It has no source selection or volume control.
However, the input sensitivity (I don't have the figure on me) is such that these could be done passively.
So, you could either build in a switched source selsctor and volume control, or, build a "passive preamp".
There is hardly any difference in the amp complexity between balanced and unbalanced. But there is in the power supply. There are 2 extra stabilized voltage rails required.
When choosing between balanced and unbalanced, you musy consider complications to the volume control. Either you must use a 4 gang control, or a tapped transformer, or convert to unbalanced - just for the volume control.
There is a lot to think about. You should think hollistically.
Similarities:
Yes there are some similarities between mine and Ciuffoli’s.
In fact, you might consider that as you are going to use a 300B rather than a VV32, you might get away with his input stage. I don't know if that would work for sure. There are many variables.
There is no problem using a 300B with my design.
A VV32B would not work in his design.
As soon as I can get my digital camera back, I'll send you a snapshot.
Cheers,
Output transformers
If I can stick my oar in here, how do your recommended output transformers measure? Sadly, many transformers fail at the bench - let alone on listening tests.
I consider it reasonable for a transformer to be able to deliver full power at 20Hz with only a mild increase in distortion, but will perhaps relax that to 25Hz for SE.
Similarly, I expect a push-pull transformer to have perfect balance, yet some cause unresolvable HF problems on square waves due to imbalances.
Neither of these defects is excusable, yet the output transformer is crucial (although often skimped commercially).
Finally, if they pass all these tests, do we need to be able to speak Dutch, or is the proprietor able to cope with uneducated philistines?
If I can stick my oar in here, how do your recommended output transformers measure? Sadly, many transformers fail at the bench - let alone on listening tests.
I consider it reasonable for a transformer to be able to deliver full power at 20Hz with only a mild increase in distortion, but will perhaps relax that to 25Hz for SE.
Similarly, I expect a push-pull transformer to have perfect balance, yet some cause unresolvable HF problems on square waves due to imbalances.
Neither of these defects is excusable, yet the output transformer is crucial (although often skimped commercially).
Finally, if they pass all these tests, do we need to be able to speak Dutch, or is the proprietor able to cope with uneducated philistines?
Hi 8010,
I admit that I have not yet measured the LF power bandwidth. My ears however are very happy. The transformer size would not be out of place in a 100w P-P amplifier. It must be my next check. I'll report back on this.
When I was asking him for quotes, I kept saying "make it larger", so there is no compromise at LF, but he was insistant that making it any larger would be wasting my money.
At HF however, I was surprised to see the residual 44.1 KHz from my CD player on the speaker terminals. This is a commercial midrange Sony player with original DAC and filtering. The last time I checked (and I have not made final measurements), the -3dB point of the overall system was about 35KHz. This of course takes into account the driver transformer. The output transformer alone will go farther.
IMO this is a good HF response for a 10K primary.
The company owner Wil Blaauw, speaks accented, but perfectly understandable English. He will understand any nuances, and has a good sense of humour.
Wil is not good at answering his e-mail, so the best way to communicate is to phone him. After that, business is best conducted by Fax.
He is mainly in the power transformer business. This is an extra venture for him. He will not get rich selling audio transformers at these prices, so please allow him time to interleave this work with his main business.
Cheers,
I admit that I have not yet measured the LF power bandwidth. My ears however are very happy. The transformer size would not be out of place in a 100w P-P amplifier. It must be my next check. I'll report back on this.
When I was asking him for quotes, I kept saying "make it larger", so there is no compromise at LF, but he was insistant that making it any larger would be wasting my money.
At HF however, I was surprised to see the residual 44.1 KHz from my CD player on the speaker terminals. This is a commercial midrange Sony player with original DAC and filtering. The last time I checked (and I have not made final measurements), the -3dB point of the overall system was about 35KHz. This of course takes into account the driver transformer. The output transformer alone will go farther.
IMO this is a good HF response for a 10K primary.
The company owner Wil Blaauw, speaks accented, but perfectly understandable English. He will understand any nuances, and has a good sense of humour.
Wil is not good at answering his e-mail, so the best way to communicate is to phone him. After that, business is best conducted by Fax.
He is mainly in the power transformer business. This is an extra venture for him. He will not get rich selling audio transformers at these prices, so please allow him time to interleave this work with his main business.
Cheers,
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