Both look similar to me, the ebay prices are kind of high though.
Those are available at Reichelt.de or Conrad.de for less than 10 Euros.
Farnell or digikey should have them at more reasonable prices.
https://uk.farnell.com/w/c/transformers/audio-transformers/prl/results?st=line transfomer
You can get proper audio transformers from Hammond at digikey for the same price:
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Maybe you can check some electronic components stores in the UK and they will have cheaper line transformers too. I think even Thomann has them.
Those are available at Reichelt.de or Conrad.de for less than 10 Euros.
Farnell or digikey should have them at more reasonable prices.
https://uk.farnell.com/w/c/transformers/audio-transformers/prl/results?st=line transfomer
You can get proper audio transformers from Hammond at digikey for the same price:
Blocked
Maybe you can check some electronic components stores in the UK and they will have cheaper line transformers too. I think even Thomann has them.
I will go with the one on eBay. By the end, I think £13 is ok.
I've checked many stores and some charge £5 in shipping costs and others £10.
After that being applied, it is more expensive than eBay.
The only way to get free shipping is if I spend more, which is an option.
Let's see.
Best regards,
Pedro
I've checked many stores and some charge £5 in shipping costs and others £10.
After that being applied, it is more expensive than eBay.
The only way to get free shipping is if I spend more, which is an option.
Let's see.
Best regards,
Pedro
I've found out that here in Germany the cheapest soucrce for transormers like these is Security Check. This company has been bought out by Conrad electronic some decades ago, offers about the same, but is much cheaper than it's mother company.
I bought each a pair of the smallest Visaton line transformers, the TR 6.8 and the TR 10.16. Their lamination stacks measure about 40 x 32 x 17 mm for the 6 watts TR 6.8, and 48 x 40 x 17 mm for the 10 watts TR 10.16, respectively. The 6.8 transforms to a primary impedance of 8 kohms, the 10.16 to 16 kOhms. This one also has a secondary CT. Primary CT's are at 2.5 watts and 6 watts, respectively.
Best regards!
I bought each a pair of the smallest Visaton line transformers, the TR 6.8 and the TR 10.16. Their lamination stacks measure about 40 x 32 x 17 mm for the 6 watts TR 6.8, and 48 x 40 x 17 mm for the 10 watts TR 10.16, respectively. The 6.8 transforms to a primary impedance of 8 kohms, the 10.16 to 16 kOhms. This one also has a secondary CT. Primary CT's are at 2.5 watts and 6 watts, respectively.
Best regards!
Attachments
You guys are lucky with the variety available there.
The best I could find was the monacor for £8.5 at CPC, which is not bad. But to not pay shipping costs I have to spend £20, at least.
That is not a problem, since I have to buy the rest of the components: jacks, capacitors, potentiometers, etc.
Everything will cost just a bit above £20. If I add a Hammond 1590B case, it will be £9 more.
Cheers,
Pedro
The best I could find was the monacor for £8.5 at CPC, which is not bad. But to not pay shipping costs I have to spend £20, at least.
That is not a problem, since I have to buy the rest of the components: jacks, capacitors, potentiometers, etc.
Everything will cost just a bit above £20. If I add a Hammond 1590B case, it will be £9 more.
Cheers,
Pedro
I some questions, as I am starting the design:
From the the characteristic curves, the ra of the 6N16B seems to be around 5K ohm and I was putting there 2x that value (10k). However, I've seen some schematics using 100k !!! Is this correct? For the 12AX7, which has an ra of 50k ohm, that looks ok but for the 6N16B it looks weird.
Regarding the bias I see some designs, biasing the tube for low current and, so, the bias point is very close to the curved area. Shouldn't the bias be on the linear part of the curve?
Thanks,
Pedro
From the the characteristic curves, the ra of the 6N16B seems to be around 5K ohm and I was putting there 2x that value (10k). However, I've seen some schematics using 100k !!! Is this correct? For the 12AX7, which has an ra of 50k ohm, that looks ok but for the 6N16B it looks weird.
Regarding the bias I see some designs, biasing the tube for low current and, so, the bias point is very close to the curved area. Shouldn't the bias be on the linear part of the curve?
Thanks,
Pedro
Pedro,
I fully agree with you! With an internal plate resistance of just 5 kohms, increasing the external plate resistor from, say, 20 kohms to 100 kohms won't yield in a significant increase of gain (from 4 to 4.8 times gm in this example). You'd just need much more supply voltage to get the tube working sufficiently.
Regarding the AX 84 October Studio suggestion: You might omit the FX loop section and have an amplifier with just five tubes, including the rectifier. But it won't be a subminiature tube challenge anymore.
Best regards!
I fully agree with you! With an internal plate resistance of just 5 kohms, increasing the external plate resistor from, say, 20 kohms to 100 kohms won't yield in a significant increase of gain (from 4 to 4.8 times gm in this example). You'd just need much more supply voltage to get the tube working sufficiently.
Regarding the AX 84 October Studio suggestion: You might omit the FX loop section and have an amplifier with just five tubes, including the rectifier. But it won't be a subminiature tube challenge anymore.
Best regards!
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I always thought of the 6N16B as something like a 12AU7. Check some famous amps that use the 12AU7 as a gain stage and you will have something to start with.
The large resistors might be there to reduce the current or are just a gain stage copy&paste from a famous amp, with the wrong tube though. When I do something like this, I like to use tubes with a similar MU.
The 6N16B is more on the low MU ballpark. Good for the output stage, but a bit current hungry for a normal gain stage. The 6N17B is better, and the 6N21B would be closer to a 12AX7.
The large resistors might be there to reduce the current or are just a gain stage copy&paste from a famous amp, with the wrong tube though. When I do something like this, I like to use tubes with a similar MU.
The 6N16B is more on the low MU ballpark. Good for the output stage, but a bit current hungry for a normal gain stage. The 6N17B is better, and the 6N21B would be closer to a 12AX7.
Hi,
I really like to understand how things work.
Maybe I will end up using an existing circuit, but I would like to be able to understand how to tweak it according to my "taste".
Best regards,
Pedro
When I was working at a college the students designed, designed and designed again until the instructor said just build it and that will give you some knowledge where to go from there. After fussing about for so long they may have found it was not something that did not really work out in practice. Mark II is always better.
@carlnoe Are you interested in building a Champ 5F1 circuit, but using Russian subminiature tubes and recalculating component values to work with those tubes?
If you are, I am thinking of something similar. I was going to use a Deluxe 5e3 circuit, but change it to work with 6n17b's and 6p30b-r output tubes.
Maybe we can twist each other's arm until we can agree on basic circuit, transformers, and redesign the circuit together? I would consider doing a Champ 5F1 if that's what everyone else wants to do, but I'm pretty firm on the 6n17b preamp and 6p30b-r output since they seem to be the closest Russian subminiature alternative to a 12ax7 and 6V6, and I have them.
If you are, I am thinking of something similar. I was going to use a Deluxe 5e3 circuit, but change it to work with 6n17b's and 6p30b-r output tubes.
Maybe we can twist each other's arm until we can agree on basic circuit, transformers, and redesign the circuit together? I would consider doing a Champ 5F1 if that's what everyone else wants to do, but I'm pretty firm on the 6n17b preamp and 6p30b-r output since they seem to be the closest Russian subminiature alternative to a 12ax7 and 6V6, and I have them.
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