Hello everybody,
I have a friend of mine who is a skilled tech to build me a Pass Labs First Watt F4 clone which I will use coupled with my vintage Audio Research SP9 preamp, on the excitement for the renewal of my stereo setup I kept scratching my head and ended up looking at the 120+ pages of the BA-3 front end used as a preamp and is looks like it would be a perfect mate for the F4 and not too difficult to put together even for a beginner.
Not to pollute the dedicated thread with questions about the power supply I am starting one here so that you can help me figure it all out.
As far as my understanding it takes a transformer to go from 230AC (Italy here) to the expected AC to feed the preamp stage rails, something like:
Here about the power supply boards, so far it seems doesn't matter which, it has to feed in the 18-24Vcc and if I got it right the desired output gets adjusted by the components on the PSU board, I see many implementations but to make it easier since I need to buy the BA-3 board off the DIY store I might also get the Super Regulator one(s) and combine it all within one shipping, am I correct that the latter board would do it and that it takes two to make a dual mono setup along with two single output transformers?
I see that the board comes with holes to fit the cables coming out of the transformers but on several finished setups there are screw terminals (sorry, dunno how they are called in Enlish), my guess is that the greed sockets have been soldered on the board then cables plugged in is that right and are those green things a standard size I can get off any components supplier?
Thanks for your attention
Giovanni
I have a friend of mine who is a skilled tech to build me a Pass Labs First Watt F4 clone which I will use coupled with my vintage Audio Research SP9 preamp, on the excitement for the renewal of my stereo setup I kept scratching my head and ended up looking at the 120+ pages of the BA-3 front end used as a preamp and is looks like it would be a perfect mate for the F4 and not too difficult to put together even for a beginner.
Not to pollute the dedicated thread with questions about the power supply I am starting one here so that you can help me figure it all out.
As far as my understanding it takes a transformer to go from 230AC (Italy here) to the expected AC to feed the preamp stage rails, something like:
- transformers (I'll like to make it dual mono since also the F4 is gonna be so)
- rectifiers (dunno if the PS boards act as rectifiers too)
- power supply boards
- BA-3 board
- volume pot, AC switch, input selector, RCA plugs, AC plug, cables...
Here about the power supply boards, so far it seems doesn't matter which, it has to feed in the 18-24Vcc and if I got it right the desired output gets adjusted by the components on the PSU board, I see many implementations but to make it easier since I need to buy the BA-3 board off the DIY store I might also get the Super Regulator one(s) and combine it all within one shipping, am I correct that the latter board would do it and that it takes two to make a dual mono setup along with two single output transformers?
I see that the board comes with holes to fit the cables coming out of the transformers but on several finished setups there are screw terminals (sorry, dunno how they are called in Enlish), my guess is that the greed sockets have been soldered on the board then cables plugged in is that right and are those green things a standard size I can get off any components supplier?
Thanks for your attention
Giovanni
You are asking wonderful questions, IMO. That is the best way to get started.
I am not sure that the super-regulator (this one) is the best choice for you as a novice without some help..
https://diyaudiostore.com/collections/power-supplies-accessories/products/super-regulator
As you get started. You need to determine the max signal voltage you want your pre-amp to put out. The F4 has no voltage gain. So, Dennis suggested running 30V rails, which directly ties to the maximum output signal voltage. For the BA-3, you need a positive and a negative voltage supply as referenced to a common ground. So +- 30VDC if you agree with Dennis. I do. 😀
When you look at the super-regulator specifications... can you find out how to make it into a supply that will work for you? It is not quite as simple as the one you linked to in the other thread. With the one you linked, you simply choose the desired transformer, take a measurement or two, and turn a potentiometer to fine-tune your desired DC.
For the super-regulator, you need to choose some parts properly. Notice the very nice chart that someone created. Do you find 30VDC in that chart? What is closest? Is that good enough? Do you want precisely 30? Maybe your skilled tech that built the F4 for you could also provide you some direct help with your BA-3 pre-amp? You can learn beside them as they choose the correct parts and you build it?
My suggestion for you is to purchase a PSU kit with all the parts you need or a fully built supply. Stress of finding some key parts if they are not in stock can be really bad. Ordering the wrong part (the voltage reference and some resistors in this case) would be a problem. Let someone do that for you. Yes, you might pay a bit more.
Safety - No matter what, at least on one side of the supply, you will be dealing with your mains voltage. That can hurt or even kill you. If you're unsure, please ask lots of questions or let someone do it for you. Maybe you could work on the audio side of the BA-3 and let someone else do the more dangerous part. Maybe you let your skilled tech check all your work and do the first connections to mains voltage?
Wishing your project turns out beautifully.
I am not sure that the super-regulator (this one) is the best choice for you as a novice without some help..
https://diyaudiostore.com/collections/power-supplies-accessories/products/super-regulator
As you get started. You need to determine the max signal voltage you want your pre-amp to put out. The F4 has no voltage gain. So, Dennis suggested running 30V rails, which directly ties to the maximum output signal voltage. For the BA-3, you need a positive and a negative voltage supply as referenced to a common ground. So +- 30VDC if you agree with Dennis. I do. 😀
When you look at the super-regulator specifications... can you find out how to make it into a supply that will work for you? It is not quite as simple as the one you linked to in the other thread. With the one you linked, you simply choose the desired transformer, take a measurement or two, and turn a potentiometer to fine-tune your desired DC.
For the super-regulator, you need to choose some parts properly. Notice the very nice chart that someone created. Do you find 30VDC in that chart? What is closest? Is that good enough? Do you want precisely 30? Maybe your skilled tech that built the F4 for you could also provide you some direct help with your BA-3 pre-amp? You can learn beside them as they choose the correct parts and you build it?
My suggestion for you is to purchase a PSU kit with all the parts you need or a fully built supply. Stress of finding some key parts if they are not in stock can be really bad. Ordering the wrong part (the voltage reference and some resistors in this case) would be a problem. Let someone do that for you. Yes, you might pay a bit more.
Safety - No matter what, at least on one side of the supply, you will be dealing with your mains voltage. That can hurt or even kill you. If you're unsure, please ask lots of questions or let someone do it for you. Maybe you could work on the audio side of the BA-3 and let someone else do the more dangerous part. Maybe you let your skilled tech check all your work and do the first connections to mains voltage?
Wishing your project turns out beautifully.
Hello back,
I think I am overly polluting the BA-3 thread with my questions so I guess that here I can get focused on the power supply part of the project.
The F4 was suggested by other members based on my preamp it being an AR SP9 with sufficient output to drive the F4 buffer, the idea of a new preamp came by pure curiosity of trying and build something myself and also at getting a matched mate to the F4 and relegate the SP9 to something else (I have a wonderful turntable but no space where to permanently use it so the phono stage is not mandatory and just in case it would be fun to build one in the future if the BA-3 gets to completion).
Unconditionally trusting your advise of 30V rails it is about to pick the right PS board which can supply the necessary voltage and current this latter one not being big issue it being a preamp (I have to go through the BA-3 thread beginning again to see specs as now, with yours all help, I am starting to better understand it all even tho a little step at a time).
See what I mean, this is the interesting part of it all, LEARNING!
Nope, the Super Regulator doesn't fit the bill, it doesn't get to desired 30V nor close to it whilst the Sigma 22 states as follows:
7. The output voltage adjustment of the board is as follows:
Output Voltage R10 Value Zener Diode (D5)
±36V 4.99K BZX55C12 (12V)
±30V 6.81K BZX55C12 (12V)
±27V 7.87K BZX55C12 (12V)
±24V 10K BZX55C12 (12V)
±15V 39.2K BZX55C12 (12V)
±12V not installed BZX55C12(12V)
±9V not installed BZX55C9V1 (9.1V)
±5V not installed BZX55C5V1 (5.1V) or LM336-5.0 (ADJ pin unused)
8. The relationship between the output DC voltage and the secondary AC voltage of the transformer is as follows:
Output voltage Transformer secondary
±36VDC dual 35V or 70VCT
±30VDC dual 30V or 60VCT
±27VDC dual 25V or 50VCT
±24VDC dual 25V or 50VCT
±18VDC dual 20V or 40VCT
±15VDC dual 18V or 36VCT
±12VDC dual 15V or 30VCT
±10VDC dual 15V or 30VCT
±9VDC dual 12V or 30VCT
±5VDC dual 9V or 18VCT
He could sure help, I mentioned him a while ago when we met but he is not much into solid state preamp so I didn't follow up (can't convince a Ferrari guy to like a Porsche) not to say that while I live on a small island he is in town and not even by an easy to reach spot so I can't have his direct supervision but I have another skilled friend here who could.
This makes 100% sense, I will have to order it all online given I could find the whole BOM through one shop and even tho I assume it could be achieved I would stress the whole community out each and every time I have to pick a component be it a resistor, a cap or whatever it is (I suspect you already figured that out off the other thread uh?!); I would still like and try to put it together by myself and with the local help of this skilled guy (not a close friend, quite an acquaintance but we have a mutual friend who can introduce and funny side being we share same name and surname, which in such a small place as the one where we live it's no common coincidence but we are not related at all) but if there was a kit providing boards and all components without the struggle to pick them one by one and giving the desired specs it would be soooo much better.
As a teen I still remember how many times I faced the 220VAC whilst trying and building my first kits handling a gun like soldering iron, damn, it hurts and back then we didn't have any safety switch on our electrical layout, now it is much safer, at home I installed so many switches it looks like a nuclear plant, each and every section has it's own switch.
By the way, thank you again for all the kind suggestions and if there is a kit with all the stuff to populate the boards it is so very welcome
Grazie mille
Fantastic. I was not trying to say that the super-regulator won't work for you. It could. What I was trying to point out is that it takes a bit more thought to get what you may want. Also, to the best of my knowledge, no one does it as a kit. Many times members will post their own "Mouser Carts" or full BoMs to share, which can make it much easier to order parts. However, if they didn't want the same range of DC as you, then their parts will be different from yours.
I like your idea of this thread for just your PSUs. I think you will get some great suggestions.
Ultimately, what you will want is a list of exact things to buy once you choose your PSU. I am confident many people will help with that. I am happy to help where I can.
I like your idea of this thread for just your PSUs. I think you will get some great suggestions.
Ultimately, what you will want is a list of exact things to buy once you choose your PSU. I am confident many people will help with that. I am happy to help where I can.
@ItsAllInMyHead good morning, your suggestions so far have been great and pushed me to go look out and learn some stuff which might sure be insignificant for many but really worth for my own knowledge besides I will ever make either the PS or the preamp.
Once I know I need the 30V out of the PSU to feed the BA-3 board and that, to say one, the Sigma 22 would do the job, it's about to collect the BOM to populate the boards and to then figure the values for the transformers so that I can move onto the next step.
Grazie again for your precious help
Giovanni
Once I know I need the 30V out of the PSU to feed the BA-3 board and that, to say one, the Sigma 22 would do the job, it's about to collect the BOM to populate the boards and to then figure the values for the transformers so that I can move onto the next step.
Grazie again for your precious help
Giovanni
Good Morning -
Yes. I am also not sure how well certain things will translate into Italian. Your English is exceptional.
This Sigma 22 you mentioned the other day looks like it would work well.
https://www.amb.org/audio/sigma22/
The Sigma 22 is a dual rail supply capable of 30VDC at the current necessary for your pre-amp. 😀
You said you wanted dual mono. So, one PSU per stereo channel. So, you will need two of them.
Per the manual, if you want 30VDC, you need a dual secondary transformer that will be outputting 30VAC. You will need two for dual mono.
Transformer size or rating - Since you are doing dual mono, and you said you wanted to use Toroidy transformers, 20VA is very nice. 30VA would be much more than needed, but would also work nicely for a bit more money.
We established that you are in a 220VAC country, and Toroidy specifies their transformer output voltage with a 230VAC input. So, you adjust a little bit. It is very nice that Toroidy has so many selections. Many companies do not.
Example if you bought a 30VAC Toroidy: 230/30 = 7.6666666... => 220/7.6666 = 28.7 which is a bit lower than you want. You'd want either the 31 or 32VAC secondaries. It's a regulated supply so either would likely work very nicely. I'd err being a bit higher. It will not hurt.
So a transformer with - 2 x 32 VAC secondaries. I'd choose their audio grade or their supreme audio grade. Make sure that you check the dimensions to see that it will fit your layout and chassis you desire. Many people use cardboard or paper, but if you are fancy, you can use CAD.
AMB provides an exceptional parts list for you also. They note that some of the very important parts are available from their shop. I would get all the parts in yellow italics from them. It makes it easy for you. They also provide some clear examples of brands and part types for everything else.
If you start your list / shopping cart, I'd be happy to review it, and I'm sure others would also. Remember, you'll need 2x the amount since you are building two of them.
Cheers.
Edited to add - I did notice that there are a few parts choices for the Sigma 22 that are output voltage dependent. They are clearly noted, and if you have trouble please say so. Sorry for not noticing this earlier. I called that out for the Super-Regulator, and I think it's only fair that I mention the same for the Sigma 22.
Yes. I am also not sure how well certain things will translate into Italian. Your English is exceptional.
This Sigma 22 you mentioned the other day looks like it would work well.
https://www.amb.org/audio/sigma22/
The Sigma 22 is a dual rail supply capable of 30VDC at the current necessary for your pre-amp. 😀
You said you wanted dual mono. So, one PSU per stereo channel. So, you will need two of them.
Per the manual, if you want 30VDC, you need a dual secondary transformer that will be outputting 30VAC. You will need two for dual mono.
Transformer size or rating - Since you are doing dual mono, and you said you wanted to use Toroidy transformers, 20VA is very nice. 30VA would be much more than needed, but would also work nicely for a bit more money.
We established that you are in a 220VAC country, and Toroidy specifies their transformer output voltage with a 230VAC input. So, you adjust a little bit. It is very nice that Toroidy has so many selections. Many companies do not.
Example if you bought a 30VAC Toroidy: 230/30 = 7.6666666... => 220/7.6666 = 28.7 which is a bit lower than you want. You'd want either the 31 or 32VAC secondaries. It's a regulated supply so either would likely work very nicely. I'd err being a bit higher. It will not hurt.
So a transformer with - 2 x 32 VAC secondaries. I'd choose their audio grade or their supreme audio grade. Make sure that you check the dimensions to see that it will fit your layout and chassis you desire. Many people use cardboard or paper, but if you are fancy, you can use CAD.
AMB provides an exceptional parts list for you also. They note that some of the very important parts are available from their shop. I would get all the parts in yellow italics from them. It makes it easy for you. They also provide some clear examples of brands and part types for everything else.
If you start your list / shopping cart, I'd be happy to review it, and I'm sure others would also. Remember, you'll need 2x the amount since you are building two of them.
Cheers.
Edited to add - I did notice that there are a few parts choices for the Sigma 22 that are output voltage dependent. They are clearly noted, and if you have trouble please say so. Sorry for not noticing this earlier. I called that out for the Super-Regulator, and I think it's only fair that I mention the same for the Sigma 22.
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That's too nice of you, grazie mille and, by the way, your Italian is great as well 😉
Yep, I read a little of the description and seems it would do it, there also is a BOM to get 30VDC out of it but we'll get down to this once on next chapter.
Another thing learnt today, grazie!
The supreme audio grade are over twice as much as audio grade ones, dunno how much of a substantial difference other than being incapsulated; dimensions wise I have not picked a case yet, the F4 will sit in a 4U Dissipante, I will try and keep size within a smaller footprint than regular hifi devices at least in width, I used to use CAD, good idea to figure necessary width, grazie again!
Yep, if you didn't point it out I wont have figured it out, needless to add another grazie!
In Italy we say T(w)u is meglio (better) che (than) uan
I will sure post the BOM before placing an order!
Grazie ancora e buona serata
Wonderful. For your proposed BoM / Cart with your specific manufacturer part number; might I suggest:
Use Excel or some other known spreadsheet software. Make sure to include at least the following...
The board / schematic notation - R1, R2 etc.
The manufacturer's part number for the manufacturer you have chosen
The part description from AMB
The part description - 1/8W Dale RN55 - 10ohm (example - formatting is not important, and you can cut and paste it from Mouser etc).
Then you can perhaps change the file extension to upload it here or use a file share / online document service of your choice. That way, it will be very easy to read.
Example attached - I cut and pasted from the AMB site into Excel. Took < 2 mins. Change file extension back to .xlsx from .pdf. It's just an example. and a suggestion similar to what I use. Then, when you are ready to order, you can load it straight into Mouser / Digikey etc. if you'd like. It is not fully complete.
Format as you will to your taste and share back if you like. The forum will not allow upload of .xlsx. Mods, if this is a violation of policy, please remove with my apologies.
re: the transformers. I have no personal experience with Toroidys. I have heard that they are wonderful. I am sure the standard audio grade is perfectly suitable for the application. Simply be a bit more sure that you have it placed further away from input / output wiring. You can also buy covers separately or make your own if you like. No worries. Sorry if I missed anything. Reading quickly and will come back to it later.
Patrick
Use Excel or some other known spreadsheet software. Make sure to include at least the following...
The board / schematic notation - R1, R2 etc.
The manufacturer's part number for the manufacturer you have chosen
The part description from AMB
The part description - 1/8W Dale RN55 - 10ohm (example - formatting is not important, and you can cut and paste it from Mouser etc).
Then you can perhaps change the file extension to upload it here or use a file share / online document service of your choice. That way, it will be very easy to read.
Example attached - I cut and pasted from the AMB site into Excel. Took < 2 mins. Change file extension back to .xlsx from .pdf. It's just an example. and a suggestion similar to what I use. Then, when you are ready to order, you can load it straight into Mouser / Digikey etc. if you'd like. It is not fully complete.
Format as you will to your taste and share back if you like. The forum will not allow upload of .xlsx. Mods, if this is a violation of policy, please remove with my apologies.
re: the transformers. I have no personal experience with Toroidys. I have heard that they are wonderful. I am sure the standard audio grade is perfectly suitable for the application. Simply be a bit more sure that you have it placed further away from input / output wiring. You can also buy covers separately or make your own if you like. No worries. Sorry if I missed anything. Reading quickly and will come back to it later.
Patrick
It's late so don't pay too much attention to it but if the Sigma 22 has output for two rails would it work for a dual mono the Sigma 11 rather than the 22?
It's now a bit late for me, but perhaps while I'm (and others... hopefully they will join in) are sleeping, you can also think a bit.
I did look at the Sigma 11 very briefly.
This is now your thread. You are the OP. Tell me (us) why you think it might work. Why might it not?
Silly thoughts...
What is a "dual rail" supply?
What is "dual mono"?
No need to type answers, but they are things to consider. I'm having tea before sleep and listening to music, so maybe not my best thoughts. 😀
I did look at the Sigma 11 very briefly.
This is now your thread. You are the OP. Tell me (us) why you think it might work. Why might it not?
Silly thoughts...
What is a "dual rail" supply?
What is "dual mono"?
No need to type answers, but they are things to consider. I'm having tea before sleep and listening to music, so maybe not my best thoughts. 😀
🤢
A Dual power supply is a regular direct current power supply. It can provide a positive as well as negative voltage. It ensures stable power supply to the device as well as it helps to prevent system damage. ... The dual power supply provides positive as well as negative potential with the ground
A Dual power supply is a regular direct current power supply. It can provide a positive as well as negative voltage. It ensures stable power supply to the device as well as it helps to prevent system damage. ... The dual power supply provides positive as well as negative potential with the ground
No need for the sad face. A dual rail supply is any supply that has two voltage rails. It's a nice example where the meaning is just what it sounds like (at least in English). It could be 30V and 5V. Many computer power supplies have 2, 12V rails. The voltages don't even have to be different. They also don't need to be equal and opposite relative to a common ground. If the rails are equal and opposite relative to a common ground, they are sometimes called symmetrical.
There can be many reasons for using one, and I'm sure my explanation is not perfect, but for our discussion it should be close enough.
An important piece (I think) is the basic concept of + and - DC voltages along with AC and visualizing how the electrons flow in one direction or another between parts. You don't need to understand everything to build a lovely project. I am a complete novice. However, it can be fun to learn it as you build.
Have some fun with some YouTube videos?
tl;dr - I think the 22 is the better choice vs. the 11 for your project. 😀
There can be many reasons for using one, and I'm sure my explanation is not perfect, but for our discussion it should be close enough.
An important piece (I think) is the basic concept of + and - DC voltages along with AC and visualizing how the electrons flow in one direction or another between parts. You don't need to understand everything to build a lovely project. I am a complete novice. However, it can be fun to learn it as you build.
Have some fun with some YouTube videos?
tl;dr - I think the 22 is the better choice vs. the 11 for your project. 😀
In Italian a rail is called "binario" which means both "binary" as binary system or "rail" which we associate to a train or similar but the prefix "bi" stands by "two" so that explains the scenario.
By casually reading I realise that a single rail (...) PSU does it for, say, a stabilised power supply like the ones I used to use for ham radio rigs or for simpler stuff like a DAC but for sure there is more than just that.
Well, that's why so many times the DIY kits I used to put together in my teen age went bad, I didn't bother to try and understand what does what and how it does it... it is very interesting to try and understand why and how something works and I am sure somebody (hint hint) will tell me why there needs bot a positive and negative rail in such application as the preamp.
On YT I found a video of a guy using the Sigma 22 in a power amp, interesting but it felt like it was a slo-mo, too long to say too little... any suggestion or link welcome
I am putting together the BOM with a spreadsheet as you suggested (grazie) and once done I will put it on here so you can review and suggest, I will double check and then we'll see, the good thing is that the project example is suited for a 30V output so it gets easier to arrange the BOM and still interesting to read how to calculate the right value for the diodes to obtain the desired value.
Grazie ancora e a domani for sure
Giovanni
Both the 11 and the 22 are regulated supplies. Is that what you are meaning? That means that they should provide a stable output voltage even when your mains voltage goes up or down a bit.
The 22 uses the word tracking in addition to regulating. I believe that means that any change that you make to the output voltage happens equally and oppositely to both rails. If the positive rail is +29V92 relative to GND, then the negative rail should 'automatically' be -29V92 relative to GND. You do not need to independently adjust them.
Will try to find a few and link.
All noted. Should be fun for you.
Prego.
Patrick
Good day everybody, back at it, I made a spreadsheet with components and notes to build a single Sigma 22 board, will try and upload the file here, it's an Apple Numbers spreadsheet which I hope can be opened and edited if necessary, let me know if it works then will add notes to specific component values, source etc
Grazie
Figured it out can't upload a spreadsheet, let's see if dropbox works
Grazie
Figured it out can't upload a spreadsheet, let's see if dropbox works
Hello,
Sorry for the delay. I was on vacation. I do not have dropbox, and it seems no one else has chimed in. Can you simply change the file extension to .pdf and upload here? I can change it back to the numbers extension when I receive it. Alternatively, I can send you my e-mail via PM for attachments.
Cheers,
Patrick
Sorry for the delay. I was on vacation. I do not have dropbox, and it seems no one else has chimed in. Can you simply change the file extension to .pdf and upload here? I can change it back to the numbers extension when I receive it. Alternatively, I can send you my e-mail via PM for attachments.
Cheers,
Patrick
Ciao Patrick,
I hope this finds you well after your vacation, I so much look for even a weekend myself but things here are so troublesome that's hard to even plan such a thing...
By the way, I used Apple Numbers to create a multi page spreadsheet, changed the extension into .pdf but dunno if you can revert back to the spreadsheet format, let me know otherwise we'll work through email.
Thank you so much for being so nice to me and, once you are, what about this as volume and input controls?
I hope this finds you well after your vacation, I so much look for even a weekend myself but things here are so troublesome that's hard to even plan such a thing...
By the way, I used Apple Numbers to create a multi page spreadsheet, changed the extension into .pdf but dunno if you can revert back to the spreadsheet format, let me know otherwise we'll work through email.
Thank you so much for being so nice to me and, once you are, what about this as volume and input controls?
Hi Giovanni -
Very sorry to hear that things are troubling there. I hope it passes soon and that some DIY brings you joy.
I have a Mac, so numbers is no problem. I changed the extension back to .numbers and it works just fine.
You did a very nice job IMO on the spreadsheets. I particularly like the extra tabs you made for your notes.
The next step is to populate the spreadsheet with the part numbers you will buy from your choice of supplier. The three biggest ones in the USA that I use are Mouser, Digikey, and Arrow. There are a few more. I am less familiar with what might be easiest for you in Italy. I believe Mouser is widely used, but I am unsure.
I had added a few columns as a suggested starting point in the spreadsheet I had sent you. I like to put in the manufacturer's part number, the supplier's part number, the quantity needed for one iteration of the "board" I am working on, the number of the boards, the total quantity needed for the project, and the total quantity I intend to order.
As an example the manufacturers part number for a Vishay-Dale RN55 series 1kohm 1/8W resistor for R3 is RN55D1001FB14.
The Mouser part number is 71-RN55D-F-1.0K
You need 1 per board (R3)
You need 2 for the project - you are building two for dual mono
I'd order 10 if you don't mind getting a few extra. 1k is a common value for other projects, and it's nice to have extras. However, there is not a meaningful price discount for the quantity of 10. So, if you wish to be more cost effective, you can order 2, but be careful. I like to have a few extra parts in case of an error. Your decision. Note, by comparison, you may notice that these resistors are relatively expensive. They are very nice parts, but you can look through the other recommended 'models' and choose any of them. I simply chose the first on the list.
If you have trouble locating any parts / part numbers, feel free to ask. It can be a bit tricky for your first effort, but all the "big suppliers" have very nice search functions. I simply typed in "Dale RN55" into the search bar for Mouser and started from that point forward.
Cheers,
Patrick
Very sorry to hear that things are troubling there. I hope it passes soon and that some DIY brings you joy.
I have a Mac, so numbers is no problem. I changed the extension back to .numbers and it works just fine.
You did a very nice job IMO on the spreadsheets. I particularly like the extra tabs you made for your notes.
The next step is to populate the spreadsheet with the part numbers you will buy from your choice of supplier. The three biggest ones in the USA that I use are Mouser, Digikey, and Arrow. There are a few more. I am less familiar with what might be easiest for you in Italy. I believe Mouser is widely used, but I am unsure.
I had added a few columns as a suggested starting point in the spreadsheet I had sent you. I like to put in the manufacturer's part number, the supplier's part number, the quantity needed for one iteration of the "board" I am working on, the number of the boards, the total quantity needed for the project, and the total quantity I intend to order.
As an example the manufacturers part number for a Vishay-Dale RN55 series 1kohm 1/8W resistor for R3 is RN55D1001FB14.
The Mouser part number is 71-RN55D-F-1.0K
You need 1 per board (R3)
You need 2 for the project - you are building two for dual mono
I'd order 10 if you don't mind getting a few extra. 1k is a common value for other projects, and it's nice to have extras. However, there is not a meaningful price discount for the quantity of 10. So, if you wish to be more cost effective, you can order 2, but be careful. I like to have a few extra parts in case of an error. Your decision. Note, by comparison, you may notice that these resistors are relatively expensive. They are very nice parts, but you can look through the other recommended 'models' and choose any of them. I simply chose the first on the list.
If you have trouble locating any parts / part numbers, feel free to ask. It can be a bit tricky for your first effort, but all the "big suppliers" have very nice search functions. I simply typed in "Dale RN55" into the search bar for Mouser and started from that point forward.
Cheers,
Patrick
I have not personally used that unit. I believe others have used it in combination with the BA-3 pre-amp successfully. To be perfectly clear, I have never built the BA-3 pre-amp. I have built the full amplifier, and a few other pre-amps. So, some of what I offer as advice is not from direct experience. It will be a bit of an educated guess.
I did a very quick read through of Tea-Bag's notes and instructions. I believe that you could assemble it properly as a first-time builder. It does add a bit of complexity to your build, but it seems like a very nicely supported and popular choice. So, if you do have questions, I think you will get a quick and proper answer from the community. As an example, I checked that it does take a simple AC input of between 12-22V or a DC input. I am unsure whether it would be best to get the power directly from the AC secondaries from one of your transformers, or from your DC supply. With both cases, it would be just likely be from one "channel" of your supply (dual mono PSU) which would make one have more of a load than the other. It's a very small load, but is that okay? I am sure those questions can be easily answered by people with more direct experience and knowledge. Just my
Edited to add - I know dual mono is a "neat" thing to do, but are you sure you really want that complexity for your first build? You can easily get all the parts now, and convert it later. If you choose that path, then you'd have a direct A/B to know whether dual mono is better for you in terms of sound.
Edited again to add - It looks like the DC input is max 30V, so you will be very close. If I were you, I would look in the forum for that particular selector and/or the BA-3 thread to see how those have been powered successfully and ask the AC vs. DC supply question if you can't find the answer.
Edited AGAIN! 😀 😀 - I just remembered the big voltage drop from the Sigma PSU and that you'll be using a secondary voltage above 22VAC to get your desired 30VDC rails. LOL!. So, you must ask someone if being at or just a bit over the 30VDC max for the input selector board is advisable. More coffee necessary.
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Ciao,
I hope this finds you well, here weather mixed bag, been nice till couple days ago, in fact I spent a couple days on the mainland, WOW! Then some rain, very cold which brought snow on the tip of Vesuvio and again some thin rain, today cold again with some wind... now good enough, I did an attempt at starting to populate the shopping list and as such attaching the numbers file with a .pdf extension for you to check, trouble started when looking for caps, diameter being a choice discriminator to say one.
Some items are available directly off of AMB (the Sigma 22 board producer/seller) which makes things easier, the other items I am looking for on Mouser which should make things easier for somebody with your level of patience :-D to check
As per the volume potentiometer/board I will ask on the BA-3 dedicated forum to find out if worth and if it adds too much trouble for a first timer also taking in account it needs some power to work and it would sure add complication if it takes to add another power source.
Let me try and attach the edited spreadsheet
Thank you again and have a nice day
Giovanni
I hope this finds you well, here weather mixed bag, been nice till couple days ago, in fact I spent a couple days on the mainland, WOW! Then some rain, very cold which brought snow on the tip of Vesuvio and again some thin rain, today cold again with some wind... now good enough, I did an attempt at starting to populate the shopping list and as such attaching the numbers file with a .pdf extension for you to check, trouble started when looking for caps, diameter being a choice discriminator to say one.
Some items are available directly off of AMB (the Sigma 22 board producer/seller) which makes things easier, the other items I am looking for on Mouser which should make things easier for somebody with your level of patience :-D to check
As per the volume potentiometer/board I will ask on the BA-3 dedicated forum to find out if worth and if it adds too much trouble for a first timer also taking in account it needs some power to work and it would sure add complication if it takes to add another power source.
Let me try and attach the edited spreadsheet
Thank you again and have a nice day
Giovanni