Very useful; though I will fist improve further my 12AX7 -EL34 (rewiring, tube upgrade, tuning) , before probably building the “pure Darling” or in the future your 71A project , I can use this part list for selecting my own components, because choosing the right type is always hard for me.
On your blog site, you suggest an alternative coupling capacitor, Obbligato Premium 0.22uF/600VDC. Unfortunately this has been discontinued, but a few sources have its replacement of 0.22uF/1000VDC. Would this still work? It sells for approximately 22 Euros. Thanks!
It will work well, it's an even better cap, just more expensive. When looking at a capacitor, a higher voltage rated version of the same capacitor is always of higher sound quality. You can always use a higher voltage rated value than specified, the only thing to look for is that higher rated cap is bigger. In this case you will have plenty of space so no worries.
I putting together an order for parts from Mouser and was wondering where to find the Mouser number for the "bypass w/DC Link 15 UF Kemet? There are 23 types listed on Mouser. Thanks!
Hi Dan, do a search for "kemet dclink", and then click on "film capacitors". Then it will show you a list of the available selection which is 27 at this moment. Check "in stock", then apply filter, and it went down to 15 items for me. At this time there is no 15uF available, the closest is 22uF. When you select it, it will bring up the Mfr# C4AQPEW5220M3CJ as the only available choice now. That will work well! ;) In general, any of the C4 series Kemet DCLinks will work (provided they are close in capacitance.) Alternatively you can double up two 8uF ones (in parallel) as well to get 16uF. The parts # is: C4AQIBU4800A11J - and two of these is cheaper than a single 22uF cap, this would be my choice;
@@realworldaudio Thanks very much! I recently built a pair of the voigt pipes out of spruce fir pine. Our Lowe’s sells 20 inch wide by 8 foot long spruce for about $48 per board. The sound is incredible. I used the Fostex FE206 NV for the drivers. I’m still sanding the surfaces and will send photos after I finish and do a one coat shellac.
@@realworldaudio sorry to bother you again, but can you provide a Mouser number for the 200R/1W KOA Speer carbon film resistors and the 220K/1 W KOA Speer resistors? These two items will complete my Mouser list. Thanks very much!
I contacted Mouser today for their assistance in obtaining their part numbers for the KOA Speer 200 Ohms 1W resistors (it was SPRX1CT52RR20J), but they were unable to find a KOA Speer 220K 1W resistor (the largest they found was a 1/2 W). I did find a YAGEO CFR100JR-73-220K. Would the YAGEO work as a substitute? Thanks!
@@MrCantredr The single 1/2W is plenty, even 1/4W would be already more than needed. I am recommending heavier wattage ones as they sound better. The 1/2W will be already very good, no worries. ; )
Most of the parts will be useful! Just make sure to build it on a big enough chassis to accommodate for possible upgrades. I will post soon on the chassis and parts layout & planning. ;
@@realworldaudio bro if I'm having 90db speakers already , can this amp be bridged and used as mono amps , should I go for the more powerful version with the better output transformer
@@IDontExist14 90dB will be enjoyable on small scale music, but very far from letting the amp shine. Yes, you should go for the more powerful one., that is happy to handle reasonable 90dB speakers.
@@IDontExist14 If you need more power, we can double up to power tubes per channel & use a bigger transformer that can support it. Basically, you will need the electric Darling version that has two output tubes per channel. Bridging tube amps in mono works in THEORY, but it's like putting on a single shoe on both feet and expecting to dance better. You will get the opposite result. Sure, drives loudspeaker better, but you loose every benefit of this design and sacrifice all the sound quality gains. If your goal is to drive low efficiency speakers, and then this is not the road for you. (Low efficiency speakers will work in a liited capacity until you build efficient speakers, and there will they shine). You would be better off with a push-pull design. Briefly, the Electric Darling will have double power, but if you want volume & power& playing very loud and dedicated to lower efficiency then none of these amps can be of any consideration.
I think an attenuator would be better than the pot volume or balance a 6 -8 gain attenuator surface mount resistors. you can control both sides of the gain stage from the input and output using me attenuator Yes you want you valves quite far apart ideally 3" or more to prevent EMI RF infiltration
The attenuator recommendation is superb! Indeed, the volume control is the weak link in this situation, yet it's something that every beginner can handle. Then, changing over to an attenuator it's a great learning experience of the big jump it makes. With high efficiency speakers 6-8 positions for volume attenuation is enough, we need no more. With low efficiency speakers the steps would need to be carefully tailored to the loudspeaker to hit the sweet spots. Indeed, keeping elements (tubes, iron) at proper distance is very important! ; )
They sell officially on ebay to make it easier for US customers. Their official site is, can order directly from them as well: www.tube-amps.net/Hashimoto_Products.htm
Is there an idea of meters of wire to buy? I'm considering deulund cotton silver or copper tin. Also is silver better because it matches the solder? Thank you.
I use the dead soft silver from Rio Grande. They have it in all sorts of gauges, down to AWG32. I can recommend AGW 30 or AWG32, and for higher current parallel them. For example, in the speaker cabinet internal wiring I use AWG32, 64 strands in parallel per conductor. Insulation: polyolefin heat shrink, and covering the ends with teflon tape to avoid exposure to air & corrosion. It's a hassle though at first to find a suitable insulator, so I'd recommend the Duelund cotton silver for ease of use. ;
@@realworldaudio yes, I'm recalling that previous episode with the jewellers spools now. Would it be possible to estimate the amount of completed wire length that is needed to connect the .75W darlings up?
@@a.r.5124 Let me do a calculation, and I'll post it in a video! ; ) (For each connection you need different total AWG, that is, different number of wires in parallel)
1. Be an expert instead of a beginner (+15 years of building experience, as one small mistake and it KILLS YOU); 2. x20-50 parts cost 3. Why? Mating a tube amplifier with less than adequate loudspeaker will make a mediocre result, regardless of power. SETs (at any output power) need to be mated with appropriate speakers, I HIGHLY RECOMMEND wetting feet with building proper matching loudspeaker before attempting the very expensive road to high power. Analogy: if you are a dancer, you need dancing shoes, lead boots won't cut it.
Very useful; though I will fist improve further my 12AX7 -EL34 (rewiring, tube upgrade, tuning) , before probably building the “pure Darling” or in the future your 71A project ,
I can use this part list for selecting my own components, because choosing the right type is always hard for me.
On your blog site, you suggest an alternative coupling capacitor, Obbligato Premium 0.22uF/600VDC. Unfortunately this has been discontinued, but a few sources have its replacement of 0.22uF/1000VDC. Would this still work? It sells for approximately 22 Euros. Thanks!
It will work well, it's an even better cap, just more expensive. When looking at a capacitor, a higher voltage rated version of the same capacitor is always of higher sound quality. You can always use a higher voltage rated value than specified, the only thing to look for is that higher rated cap is bigger. In this case you will have plenty of space so no worries.
@@realworldaudio thanks! I did find the 630 V version in India and have already ordered it.
Good news. I was able to cancel the order from India, and obtain the 1000v version from DIY HiFi Supply in the UK.
@@MrCantredr Superb! ;
I putting together an order for parts from Mouser and was wondering where to find the Mouser number for the "bypass w/DC Link 15 UF Kemet? There are 23 types listed on Mouser. Thanks!
Is the Mauser part number listed on another video?
Hi Dan, do a search for "kemet dclink", and then click on "film capacitors". Then it will show you a list of the available selection which is 27 at this moment. Check "in stock", then apply filter, and it went down to 15 items for me. At this time there is no 15uF available, the closest is 22uF. When you select it, it will bring up the Mfr# C4AQPEW5220M3CJ as the only available choice now. That will work well! ;) In general, any of the C4 series Kemet DCLinks will work (provided they are close in capacitance.)
Alternatively you can double up two 8uF ones (in parallel) as well to get 16uF. The parts # is: C4AQIBU4800A11J - and two of these is cheaper than a single 22uF cap, this would be my choice;
@@realworldaudio Thanks very much! I recently built a pair of the voigt pipes out of spruce fir pine. Our Lowe’s sells 20 inch wide by 8 foot long spruce for about $48 per board. The sound is incredible. I used the Fostex FE206 NV for the drivers. I’m still sanding the surfaces and will send photos after I finish and do a one coat shellac.
@@realworldaudio sorry to bother you again, but can you provide a Mouser number for the 200R/1W KOA Speer carbon film resistors and the 220K/1 W KOA Speer resistors? These two items will complete my Mouser list. Thanks very much!
I contacted Mouser today for their assistance in obtaining their part numbers for the KOA Speer 200 Ohms 1W resistors (it was SPRX1CT52RR20J), but they were unable to find a KOA Speer 220K 1W resistor (the largest they found was a 1/2 W). I did find a YAGEO CFR100JR-73-220K. Would the YAGEO work as a substitute? Thanks!
No, do not use the Yageo, it is quite poorly compared to the KOA. It looks they are out of the 1W resistors, use the 1/2W KOA instead: CF1/2C224J
Would that be a single 1/2W, or would 2 have to be used in series? Thanks!
@@MrCantredr The single 1/2W is plenty, even 1/4W would be already more than needed. I am recommending heavier wattage ones as they sound better. The 1/2W will be already very good, no worries. ; )
very nice , will try to get these parts , will these parts be used in the more powerful version as well, or just this specific version
Most of the parts will be useful! Just make sure to build it on a big enough chassis to accommodate for possible upgrades. I will post soon on the chassis and parts layout & planning. ;
@@realworldaudio bro if I'm having 90db speakers already , can this amp be bridged and used as mono amps , should I go for the more powerful version with the better output transformer
@@IDontExist14 90dB will be enjoyable on small scale music, but very far from letting the amp shine. Yes, you should go for the more powerful one., that is happy to handle reasonable 90dB speakers.
@@realworldaudio would this amp work as a mono also , so I can get more power
@@IDontExist14 If you need more power, we can double up to power tubes per channel & use a bigger transformer that can support it. Basically, you will need the electric Darling version that has two output tubes per channel. Bridging tube amps in mono works in THEORY, but it's like putting on a single shoe on both feet and expecting to dance better. You will get the opposite result. Sure, drives loudspeaker better, but you loose every benefit of this design and sacrifice all the sound quality gains. If your goal is to drive low efficiency speakers, and then this is not the road for you. (Low efficiency speakers will work in a liited capacity until you build efficient speakers, and there will they shine). You would be better off with a push-pull design. Briefly, the Electric Darling will have double power, but if you want volume & power& playing very loud and dedicated to lower efficiency then none of these amps can be of any consideration.
I think an attenuator would be better than the pot volume or balance a 6 -8 gain attenuator surface mount resistors.
you can control both sides of the gain stage from the input and output using me attenuator
Yes you want you valves quite far apart ideally 3" or more to prevent EMI RF infiltration
The attenuator recommendation is superb! Indeed, the volume control is the weak link in this situation, yet it's something that every beginner can handle. Then, changing over to an attenuator it's a great learning experience of the big jump it makes. With high efficiency speakers 6-8 positions for volume attenuation is enough, we need no more. With low efficiency speakers the steps would need to be carefully tailored to the loudspeaker to hit the sweet spots. Indeed, keeping elements (tubes, iron) at proper distance is very important! ; )
Any reputable source for Hashimoto? Search brings up mostly ebay...
They sell officially on ebay to make it easier for US customers. Their official site is, can order directly from them as well: www.tube-amps.net/Hashimoto_Products.htm
@@realworldaudio oh, ok. That is really nice of them. Thank you for the website, also.
@@danbuffington75 👍👍
Is there an idea of meters of wire to buy? I'm considering deulund cotton silver or copper tin. Also is silver better because it matches the solder? Thank you.
I use the dead soft silver from Rio Grande. They have it in all sorts of gauges, down to AWG32. I can recommend AGW 30 or AWG32, and for higher current parallel them. For example, in the speaker cabinet internal wiring I use AWG32, 64 strands in parallel per conductor. Insulation: polyolefin heat shrink, and covering the ends with teflon tape to avoid exposure to air & corrosion. It's a hassle though at first to find a suitable insulator, so I'd recommend the Duelund cotton silver for ease of use. ;
@@realworldaudio yes, I'm recalling that previous episode with the jewellers spools now. Would it be possible to estimate the amount of completed wire length that is needed to connect the .75W darlings up?
@@a.r.5124 Let me do a calculation, and I'll post it in a video! ; ) (For each connection you need different total AWG, that is, different number of wires in parallel)
How to build this but with say 50 watts x 2 @ 8 ohms
1. Be an expert instead of a beginner (+15 years of building experience, as one small mistake and it KILLS YOU); 2. x20-50 parts cost 3. Why? Mating a tube amplifier with less than adequate loudspeaker will make a mediocre result, regardless of power. SETs (at any output power) need to be mated with appropriate speakers, I HIGHLY RECOMMEND wetting feet with building proper matching loudspeaker before attempting the very expensive road to high power. Analogy: if you are a dancer, you need dancing shoes, lead boots won't cut it.