Amplifier Modules and PCBs For Sale

[truepaul]

I got a note today from JLester / or someone managing his ebay account:

"Due to Covid-19 our local post office here does not have international shipping yet.
Currently we are finding alternative courier.
We will contact you once we are able to have access on international shipping.
Thank you and regards,
JLElectronicsPh "

 

[stef1777]

Hi!

Maybe a sign. The new IRCore350M is online in the store. The product was not in production the last time JLester posted here late March.

https://shopee.ph/IRCore350M-Mono-4...le-by-JLesterP-IRS2092S-i.35313613.6636317256

 

[AlexScan]

Ok if the IRCore appear Lester was behind, on shopee is was a clue:

"jlesterp
Active 2 Hours Ago"

... but why he don't respond to me and in this thread ?

 

[truepaul]

I dunno... but I wonder if it could be the lack of a reliable internet. I just googled subject, and it looks like internet service in Manilla has recently been down for 5 or 6 days at a time. Today, most of the city was reporting slowdowns. See for example, BusinessWeek, "Filipinos struggle to work from home in internet-challenged country." Covid-related work shutdowns have put strain on an internet system that's been difficult to use for years.

 

[Deleted member 148505]

Hello JLesterP!

Any news from your TICore260BTL project?

Your board seems to be well done. I'm a UcD180HG old user. I'll be nice to compare.

I took a break from audio since March 15 when the lockdown here was started. I'm limiting my online presence to preserve my sanity (haha) I didn't check my DIYAudio account, though I would have replied to this thread if I received email notifications.

Also we cannot send package outside of the country except for some express shipping (45 to 70USD per 500g). Now I found an alternative shipping with european post office partner, shipping fee is around twice the cost before the pandemic.

I will get back on facilitating the production of my TPA3255, hopefully before November it will be available on my eBay online shop.

Hi, is there discussion on your soft start circuit ? I'm looking to see if it would fit my needs.

I will be building a dual-monaural amp, probably with two 200VA transformers. From recent reading on diyaudio and elsewhere, I'd like to apply the following design specs:

Ideally, low power consumption (5v, mA circuit?)
Power to activate relay is digital (on/off vs. slow voltage rise)
Adjustable bypass delay (e.g., 100ms to 300ms)
Low cost (as fully assembled and in use) (under $30 per board?)

Thanks in advance,
Paul

Hi Paul,

My softstart circuit is controlled by 555 IC timer. Module's idle consumption is less than 75mA, Bypass delay is not adjustable, you need to change the resistor value to change the time delay. Under 30USD cost is attainable but shipping fee is still expensive due to the pandemic.

I sure hope JLesterP is OK. He posted regularly up until March 20, then nothing since then.

I'm good, thanks for the concern, actually I'm holed up here in my residence for months now , I'm working from home and I go outside only when necessary. Thank God we haven't got Covid-19, but the situation here in our region is worsening.

Ok if the IRCore appear Lester was behind, on shopee is was a clue:

"jlesterp
Active 2 Hours Ago"

... but why he don't respond to me and in this thread ?

Hi Alex, I replied to your email last week. Thanks!

I dunno... but I wonder if it could be the lack of a reliable internet. I just googled subject, and it looks like internet service in Manilla has recently been down for 5 or 6 days at a time. Today, most of the city was reporting slowdowns. See for example, BusinessWeek, "Filipinos struggle to work from home in internet-challenged country." Covid-related work shutdowns have put strain on an internet system that's been difficult to use for years.

Yes we are experiencing internet service slowdown here since the lockdown has started because most homes now are heavily using the internet.

 

[Deleted member 148505]

I believe then with the differential signal, I can operate two modules bridged. Taking the non-inverted and inverted signals to separate JLE-2000D modules. Then taking the the + output from one module and - output for another and to my 4ohm speaker load. Does this sound correct?

I suggest you use a diff to SE converter module on the class-d module's location. Because diff signal common mode noise rejection will be useless if you will use the half of it as SE signal, also you will need the ground from nanodsp if you plan to use the SE signal.

You still need a Diff to SE converter at the class-d module location, also use an additional bridging circuit if you plan to bridge the amplifier. After that you need to take + output of both class-d modules and connect it to the speaker.

My next question is will the 1000va transformer with 55v rails be sufficient to handle 2 bridged modules for a 4ohm load? What power handling should I expect in this setup? I'm planning on about 10mF capacitance for each rail, is this sufficient? Given the size of my transformer, would it be recommended to just go with a single module and SE input? I was hoping to be able to use a differential signal since the amp will be located across the room from my preamp.

With your power supply, I suggest that you just use a single JLE class-d module. With your power supply, and with a single class-d module, expect some voltage sag of around 8VDC at full power output at 4 ohms, you can get 49VAC at the output or 600W into 4 ohms output.

If you want you can still bridge it, but your power supply might overheat (if the output is at disco level), if it's for home use then your power supply will be ok, just limit the bridge output to around 60VAC (30VAC per module), since nanodsp output is 2VRMS you can lower the gain of each JLE class-d module to 15 (you need to change input resistor value).

If you don't limit the output, your power supply might overheat. Also if your power supply voltage has secondary winding, their voltage will drop too and might affect other modules which are using the power supply.

Thank you,
Lester

 

[gtose]

Hey Lester,

Thanks for the response and glad you’re back!

will the 1000va transformer with 55v rails be sufficient to handle 2 bridged modules for a 4ohm load?

I believe I misspoke here, it has 55VAC secondaries, so about 77VDC rails. Does this change your recommendation on the estimated power output for one / two modules?

Good call on the noise rejection for the direct balanced input, I hadn’t considered that. Looks like I’ll start looking into differential to single ended convertors, seems like some options on ebay and around the forum.

Thanks again,
Greg

 

[AlexScan]

I see your mail Lester, glad to read you again...

The new IRCore is available ?

You put it on QA400 for measurement ?

 

[Deleted member 148505]

Hey Lester,

Thanks for the response and glad you’re back!



I believe I misspoke here, it has 55VAC secondaries, so about 77VDC rails. Does this change your recommendation on the estimated power output for one / two modules?

Good call on the noise rejection for the direct balanced input, I hadn’t considered that. Looks like I’ll start looking into differential to single ended convertors, seems like some options on ebay and around the forum.

Thanks again,
Greg

With 55VAC secondaries and 77VDC rails, you need at least 2000VA transformer if you want to bridge the 2 modules. With 55VAC secondaries and a beefy transformer, my estimate (77V-17V DC voltage drop at full power) is that if you bridge the 2 modules will get around 85V RMS output into 4 ohms or 1800W.

JLE-2000D module can handle 1KW into 2 ohms load though it needs good heatsink and cooling.

 

[Deleted member 148505]

I see your mail Lester, glad to read you again...

The new IRCore is available ?

You put it on QA400 for measurement ?

Yes, it's already available on my eBay store.

Attached QA400 measurements

 

[Deleted member 148505]

TPA3255 V1.0

TPA3255 TICore260BTL V1.0 QA400 measurements 1W to 100W 4 ohms load.

Production version (V1.1) has DIP IC's, balanced input, and has an option for upgrading inductors to a larger type (1D23A). Heatsink is also upgradable to ATS-TI10P-519-C1-R3

 

[Deleted member 148505]

Line Level Signal Detect

Line Level Signal Detect available on my eBay shop.
Updated version. I changed all parts to through hole for easier assembly.

 

[Deleted member 148505]

TPA3255 TICore260BTL V1.0

I tested the sound of my TPA3255 V1.0 prototype with my JBL 230 and it sounds very good even though it only uses NE5532 opamps.

After I listened on speakers, I retested it again on my QA400 and got better results, wiring change on my balanced interface affected the measurements.

200W measurement is worse than generic TPA3255 on QA401 blogs, I think the 1D17A inductor is the culprit. Using 1D23A will get better measurement on >100W power.

My TICore260BTL version 1.1 will be available in mid September. (attached snapshot of design)

 

[AlexScan]

Ok great news... you prefer the sounds of tpa3255 or IRS on your JBL ?

Be sure with LME48960 (my best sounding OPA, better than OPA1612/1656) and 1D23A the sound (and the measurements) will be better...

Lelon for the 4 tank caps is not a good choice Lester (value?), i think Pana FC much be really better for a reasonnable price...

 

[stef1777]

Hi JLE,

Why when we go on your shop on eBay, we can't see the products?

jlelectronicsph sur eBay

We can find some of the products when using Search on eBay but not all.

 

[Deleted member 148505]

Hi JLE,

Why when we go on your shop on eBay, we can't see the products?

jlelectronicsph sur eBay

We can find some of the products when using Search on eBay but not all.

You can try to visit ebay.com instead of ebay.fr so that you can see available products. You can also pm me here and we can do the transaction through paypal.

 

[Deleted member 148505]

Ok great news... you prefer the sounds of tpa3255 or IRS on your JBL ?

Be sure with LME48960 (my best sounding OPA, better than OPA1612/1656) and 1D23A the sound (and the measurements) will be better...

Lelon for the 4 tank caps is not a good choice Lester (value?), i think Pana FC much be really better for a reasonnable price...

I haven't tried to listen to my IRCore350M but I already stress tested them. THD is on par with IRAUDAMP7 reference design and my amp is more powerful (0.05% THD+N on 350W 4ohms)

When I tested my TPA3255 on my JBL Studio 230, highs/treble are on another level, it is soft and smooth, the bass is like 3D, bass guitar and drums are more realistic maybe because highs are better, I've read somewhere that treble also affects the perception of bass. Also the speaker is dead silent, it's like there's no connected amplifier on the speaker.

I can't find LME48960 on Mouser, RS Philippines, or Element14. I have lm49720 here and I will order 1D23A on mouser and will use them for new measurements.

Since opamps will be socketed and replaceable, only NE5532 will be provided. I will leave the opamp and capacitor upgrades to audio DIYers.

 

[Deleted member 148505]

Lelon for the 4 tank caps is not a good choice Lester (value?), i think Pana FC much be really better for a reasonnable price...

Capacitor value installed is 4 * 1200uf 80V.

 

[stef1777]

You can try to visit ebay.com instead of ebay.fr so that you can see available products. You can also pm me here and we can do the transaction through paypal.

Hi Lester!

Same with ebay.com. If I click on "Items for sale" no product.

 

[danschy]

Not sure the issue, but I'm seeing products.