Thanks!
I've replaced IC7 and that potmeter to a non inverting opamp at the woofer channel for a gain a bit higher than 1. I will test the best gain settings when I have my speaker.
Question, why no coupling capacitor after the input buffer?
Hi,
First off thanks for a brilliant thread. Although I've done a bit of turntable and Speaker building over the years this is my first foray into DIY electronics. It all started when I decided to look for an amp for my new hobby room where I'd put together some wall mounted Alpair 7p drivers in flat MLTL cabinets using XRK's design over on the full range forum. A friend said I should try the SMSL SA36a Pro amp and at just £38 delivered from Amazon UK it seemed churlish not to. To be honest I was a bit sniffy about Class D - my main amps are both Class A, Sugden A21SE and Ming Da Piccolo. How wrong was I! This little amp is quite amazing. Trouble is I started reading this thread and the one over on Audio Circle (I'm up to page 592 here). The obvious thing to do was to change the rather puny PSU that comes with this amp. First I tried SLA battery power but to be honest I couldn't hear a lot of difference. Then, after seeing someone recommending a Mascot PSU which is available over here I spotted one on ebay and picked it up for a fraction of the new price. Now that did make a difference. Oh dear I was hooked!
Next big mistake was to try the SMSL in my main system. Not expecting much I replaced the Sugden with the SMSL. Rest of system used was a Vortexbox feeding a Meridian Director DAC then out to a pair of Proac Response 1.5 speakers. Did the SMSL cope? It certainly did! Detail and soundstage were all there and there was plenty of volume for the 23X14ft room. Sound was exceptionally smooth and the only criticism was a little reduction in dynamics. I kept this going for a couple of days just in case I was kidding myself then tried my Frugel Horn XL's with Alpair 10p drivers. Same result except now the dynamics were back. So here I am absolutely hooked and wondering what a fully modded TPA3116 board would do.
I've ordered a pair of blue black boards and have been assembling the bits and pieces to start modding. All this is a bit like learning a new recipe - you follow it carefully because you don't understand the importance of individual ingredients but after a while you make it your own. You guys obviously understand the recipe but use subtly different ingredients which makes life difficult for us newbies but I think I'm getting there!
My plan is to keep one board stock and make changes one at a time on the other. To this end I've built a little passive preamp using a shunted pot - it gave me practice with soldering and following a simple wiring diagram. Anyway, enough of my ramblings, here's my question. I'm tempted by the transformer upgrade and if I'm going to do this there seems little point doing the decoupling caps upgrade. A UK ebay seller is offering some NOS Lundahl LL1521B transformers.
There's little information out there on these apart from a brief note on the Lundahl site:
"The LL1521B is a high impedance line input transformer, very similar to the LL1540 but with a slight stepup. Turns ratio 1 + 1 : 2.28
Usage:
In+ pin 1 (left row, bottom pin when viewed from component side)
In- pin 3
connect pin 2 + pin 4
Out+ pin 5 (right row, bottom pin when viewed from component side)
Out- pin 8
Shields pin 6"
Do you think these would be suitable for the input transformer upgrade?
Many thanks to all the contributors here and especially to those who created the WIKI.
Cheers, Ian
First off thanks for a brilliant thread. Although I've done a bit of turntable and Speaker building over the years this is my first foray into DIY electronics. It all started when I decided to look for an amp for my new hobby room where I'd put together some wall mounted Alpair 7p drivers in flat MLTL cabinets using XRK's design over on the full range forum. A friend said I should try the SMSL SA36a Pro amp and at just £38 delivered from Amazon UK it seemed churlish not to. To be honest I was a bit sniffy about Class D - my main amps are both Class A, Sugden A21SE and Ming Da Piccolo. How wrong was I! This little amp is quite amazing. Trouble is I started reading this thread and the one over on Audio Circle (I'm up to page 592 here). The obvious thing to do was to change the rather puny PSU that comes with this amp. First I tried SLA battery power but to be honest I couldn't hear a lot of difference. Then, after seeing someone recommending a Mascot PSU which is available over here I spotted one on ebay and picked it up for a fraction of the new price. Now that did make a difference. Oh dear I was hooked!
Next big mistake was to try the SMSL in my main system. Not expecting much I replaced the Sugden with the SMSL. Rest of system used was a Vortexbox feeding a Meridian Director DAC then out to a pair of Proac Response 1.5 speakers. Did the SMSL cope? It certainly did! Detail and soundstage were all there and there was plenty of volume for the 23X14ft room. Sound was exceptionally smooth and the only criticism was a little reduction in dynamics. I kept this going for a couple of days just in case I was kidding myself then tried my Frugel Horn XL's with Alpair 10p drivers. Same result except now the dynamics were back. So here I am absolutely hooked and wondering what a fully modded TPA3116 board would do.
I've ordered a pair of blue black boards and have been assembling the bits and pieces to start modding. All this is a bit like learning a new recipe - you follow it carefully because you don't understand the importance of individual ingredients but after a while you make it your own. You guys obviously understand the recipe but use subtly different ingredients which makes life difficult for us newbies but I think I'm getting there!
My plan is to keep one board stock and make changes one at a time on the other. To this end I've built a little passive preamp using a shunted pot - it gave me practice with soldering and following a simple wiring diagram. Anyway, enough of my ramblings, here's my question. I'm tempted by the transformer upgrade and if I'm going to do this there seems little point doing the decoupling caps upgrade. A UK ebay seller is offering some NOS Lundahl LL1521B transformers.
There's little information out there on these apart from a brief note on the Lundahl site:
"The LL1521B is a high impedance line input transformer, very similar to the LL1540 but with a slight stepup. Turns ratio 1 + 1 : 2.28
Usage:
In+ pin 1 (left row, bottom pin when viewed from component side)
In- pin 3
connect pin 2 + pin 4
Out+ pin 5 (right row, bottom pin when viewed from component side)
Out- pin 8
Shields pin 6"
Do you think these would be suitable for the input transformer upgrade?
Many thanks to all the contributors here and especially to those who created the WIKI.
Cheers, Ian
Hi,
First off thanks for a brilliant thread. Although I've done a bit of turntable and Speaker building over the years this is my first foray into DIY electronics. It all started when I decided to look for an amp for my new hobby room where I'd put together some wall mounted Alpair 7p drivers in flat MLTL cabinets using XRK's design over on the full range forum. A friend said I should try the SMSL SA36a Pro amp and at just £38 delivered from Amazon UK it seemed churlish not to. To be honest I was a bit sniffy about Class D - my main amps are both Class A, Sugden A21SE and Ming Da Piccolo. How wrong was I! This little amp is quite amazing. Trouble is I started reading this thread and the one over on Audio Circle (I'm up to page 592 here). The obvious thing to do was to change the rather puny PSU that comes with this amp. First I tried SLA battery power but to be honest I couldn't hear a lot of difference. Then, after seeing someone recommending a Mascot PSU which is available over here I spotted one on ebay and picked it up for a fraction of the new price. Now that did make a difference. Oh dear I was hooked!
Next big mistake was to try the SMSL in my main system. Not expecting much I replaced the Sugden with the SMSL. Rest of system used was a Vortexbox feeding a Meridian Director DAC then out to a pair of Proac Response 1.5 speakers. Did the SMSL cope? It certainly did! Detail and soundstage were all there and there was plenty of volume for the 23X14ft room. Sound was exceptionally smooth and the only criticism was a little reduction in dynamics. I kept this going for a couple of days just in case I was kidding myself then tried my Frugel Horn XL's with Alpair 10p drivers. Same result except now the dynamics were back. So here I am absolutely hooked and wondering what a fully modded TPA3116 board would do.
I've ordered a pair of blue black boards and have been assembling the bits and pieces to start modding. All this is a bit like learning a new recipe - you follow it carefully because you don't understand the importance of individual ingredients but after a while you make it your own. You guys obviously understand the recipe but use subtly different ingredients which makes life difficult for us newbies but I think I'm getting there!
My plan is to keep one board stock and make changes one at a time on the other. To this end I've built a little passive preamp using a shunted pot - it gave me practice with soldering and following a simple wiring diagram. Anyway, enough of my ramblings, here's my question. I'm tempted by the transformer upgrade and if I'm going to do this there seems little point doing the decoupling caps upgrade. A UK ebay seller is offering some NOS Lundahl LL1521B transformers.
There's little information out there on these apart from a brief note on the Lundahl site:
"The LL1521B is a high impedance line input transformer, very similar to the LL1540 but with a slight stepup. Turns ratio 1 + 1 : 2.28
Usage:
In+ pin 1 (left row, bottom pin when viewed from component side)
In- pin 3
connect pin 2 + pin 4
Out+ pin 5 (right row, bottom pin when viewed from component side)
Out- pin 8
Shields pin 6"
Do you think these would be suitable for the input transformer upgrade?
Many thanks to all the contributors here and especially to those who created the WIKI.
Cheers, Ian
My first thought on reading this was "Noooo, not the blue/blacks!!!".
Of the available boards, theblue/black seems quite "low" on the scale, with the SMSL SA60 and Gmarsh DIY design rated highly.
Others.... sit in the middle depending on accuracy of assembly and component choice.
J.
Thanks for the replies but I've already committed to the blue black boards mainly because there's lots of information about modding it and most changes are through holes which my novice skills might just cope with. I was under the impression that the SA60 was a ready built amplifier and I've already got the SA 36a Pro.
Can anybody comment on the suitability of the transformers?
Can anybody comment on the suitability of the transformers?
Thanks,
Most of the posts I've read about transformers seem to be positive but they tend to be ones with 1:1 ratio. The ones I'm looking at state "Turns ratio 1 + 1 : 2.28" i.e. some gain. That's why I'm wondering if they are suitable. As for price, well they are very reasonable.
Most of the posts I've read about transformers seem to be positive but they tend to be ones with 1:1 ratio. The ones I'm looking at state "Turns ratio 1 + 1 : 2.28" i.e. some gain. That's why I'm wondering if they are suitable. As for price, well they are very reasonable.
YJ 2.0 red board volume pot bypass
This may have been covered somewhere already, so apologies in advance if that is so...
I'd like to remove the volume pot on the board so I can use a separate preamp such as the Guanzo 6N3 two tube based one, or my Pass B1.
I assume I jump certain parts of the board where the stock 50k volume pot is removed with two 47k ohm resistors.
Could anyone show me with a sketch or photo how to make the connections?
Reason for this question:
I've found in the past that running an amp such as this with the volume pot "wide open" / turned to maximum position while using a separate preamp results in a less desirable sound as opposed to using no preamp and only the volume control on the amp. Yet, I am curious to see what this amp would sound like if converted into a straight power amp.
Thanks,
Mark
This may have been covered somewhere already, so apologies in advance if that is so...
I'd like to remove the volume pot on the board so I can use a separate preamp such as the Guanzo 6N3 two tube based one, or my Pass B1.
I assume I jump certain parts of the board where the stock 50k volume pot is removed with two 47k ohm resistors.
Could anyone show me with a sketch or photo how to make the connections?
Reason for this question:
I've found in the past that running an amp such as this with the volume pot "wide open" / turned to maximum position while using a separate preamp results in a less desirable sound as opposed to using no preamp and only the volume control on the amp. Yet, I am curious to see what this amp would sound like if converted into a straight power amp.
Thanks,
Mark
Mark,
Listening to the new $10 dual chip TPA3116 with it's volume control intact I am absolutely smitten with it's sound paired with a Nobsound tube preamp. No way would I consider removing it.
Listening to the new $10 dual chip TPA3116 with it's volume control intact I am absolutely smitten with it's sound paired with a Nobsound tube preamp. No way would I consider removing it.
hey Poultrygeist,
Could you give me links to the preamp and to that exact dual chip amp you mentioned?
I'd like to try both.
Thanks,
Mark
Could you give me links to the preamp and to that exact dual chip amp you mentioned?
I'd like to try both.
Thanks,
Mark
Is this the dual chip amp?
Mark
TPA3116 D2 Dual Channel 2 100W Digital Audio Amplifier Module for Arduino | eBay
Mark
TPA3116 D2 Dual Channel 2 100W Digital Audio Amplifier Module for Arduino | eBay
About the Ganzo, there is a recent thread and probably many older ones too, hilarious advice last thread 🙂
Poultrygeist,
Is the dual chip board at all decent / musical without the tube preamp ?
Is the dual chip board at all decent / musical without the tube preamp ?
Boards arrived this morning from China - around 2 weeks. They are not the original blue/blacks but the HSDZ copies of that copy🙂. I've wired one up and it works fine. Got to test the other one now and then try and figure out how to plug in the transformers. From what I've read you remove the decoupling caps then replace with the transformers. I've seen a picture somewhere but can't find it at the moment but any advice would be much appreciated.
If you are planning on going to town with the board, why not swap the inductors and do other tweaks first so that the board remains more managable (mod wise) until you get to the input transformers ?