RTR SSR Headphone Amplifier DC Protection Modules GB

[jhofland]

hello Anand,

BSS138's from other vendors are just fine to use. The Toshiba TLP3906's, on the other hand, don't have a substitute I'm aware of without a board redesign. The part numbers do have a couple of suffixes, i.e., (E, that I don't think make a difference in the application. PM me and I may be able to help with supplying a modest number of the opto's.

 

[xrk971]

Hi Anand,
The TLP3906’s will be back in stock mid December I think. I actually need to order hundreds of these for another project so keeping them on my radar.

Setting the trip point at 50mV might be a bit low and you might get inadvertent shut off of your music.

If you set it at 200mV that’s about 1.3mW dissipation into 32 ohm headphones. I think most headphones can handle 1.3mW. That’s a loud pop on IEMs that are 115dB/mW, but they won’t be damaged which is what we want to avoid.

50mV is only 78uW into 32ohms.

 

[poseidonsvoice]

So do you guys think a 10k value would be better instead of 2.2k for R6,R7, R10 and R11? I don’t anticipate use for IEM’s, just planar magnetics and dynamic headphones.

Best,
Anand.

 

[randytsuch]

Wondering if these boards will work for my somewhat unique use case.

I'm gathering parts to build a Sissysit amp. Its a class A amp based on Nelson's designs, using a Tokin THF51 SIT as the power output device.
Power supply will be in the +/- 24 to 25 VDC range. Plan to bias it at around 1.2 A

The Sissysit will be driving my HE6SE headphones. They are very inefficient, so many people use small (or larger) speaker amps to drive them.
I currently use a Amp Camp Amp to drive, but want to upgrade.

Voltage in from my rails to this board is within its range.
Is there any reason this wont' work for my application?

TIA
Randy

 

[xrk971]

Hi Randy,
It sounds like the power amp (speaker) RTR SSR may be what you need. Those are available for immediate shipping from my shop for $120/pair.

https://www.etsy.com/listing/932716741/rtr-ssr-speaker-protection-gen23?ref=shop_home_recs_3&crt=1
They will also give you added benefit of turn on delay for no thump and instant off (via either open collector logic from your PSU or MCU, or via included bonus low capacitance PSU board) for no turn off thump.

Low capacitance PSU for SSR power (connect to main trafo secondary):

Thread is here:
https://www.diyaudio.com/community/...sr-dc-speaker-protection-and-delay-gb.340694/
To answer your question if the headphone ones would work, yes - the MOSFETs are rated for quite a high value and they could be used for speakers. The wire connections are smaller Molex KK 0.1in pitch though vs larger 0.250 Faston tabs or Molex MiniFit Jr connectors.

 

[jhofland]

No reason whatsoever Randy. They ought to work just fine.

 

[randytsuch]

@jhofland
Great, thanks for the confirmation.

@xrk971
I know about your speaker protection board, just seems like overkill for my project.

I think I'll buy the headphone protection board, and give it a try.
HE6 is 54 ohms, so it will pull a lot less current than a speaker, and I'll hard wire/solder the connections, so I'm not too worried about the smaller connector.

Randy

 

[xrk971]

I might have a few TLP3906’s left if you can’t find them. Parts are a total nightmare to source lately.

 

[randytsuch]

I might have a few TLP3906’s left if you can’t find them. Parts are a total nightmare to source lately.

Thanks, looks like I can get some, but I'll keep that in mind.

On your etsy shop, there is a $15 and an $18 headphone protection PWB.
What's the difference? It wasn't obvious to me.

Thanks
Randy

 

[xrk971]

I wasn’t aware that I had two prices? They should be the same and two color choices. I only see $18 bit if you see a $15, I’ll sell it at the listed price. That’s strange.

 

[randytsuch]

Is this something else?
Looks the same to me

 

[xrk971]

It’s the same. I just had the item double listed by accident. I’ll have to clean that up but you can order it for $15.

 

[randytsuch]

It’s the same. I just had the item double listed by accident. I’ll have to clean that up but you can order it for $15.

Thanks, ordered.

 

[xrk971]

Thanks for your order. Don’t forget to have a 22k resistor to GND at the left and right input to bleed off the charge on the sense caps. Your amp won’t know the difference of driving a 22k load to ground.

 

[randytsuch]

Ok, thanks for the tip.
Is there a Mouser BOM? Or any BOM?
I want to order parts for this and another piece of my project while parts are in stock.

Thanks
Randy

 

[xrk971]

I’ll get you the BOM soon. I’m not at my computer at the momennt.

 

[xrk971]

Here is the BOM for the HPA Protection SSR v1 board:
BOM for Jhofland HPA Protect SSR v1
Qty Reference(s) Value Manufacturer MPN Mouser PN Footprint
2 C9, C10 100nF TDK CGA3E2X7R1H104K080AA 810-CGA3E2X7R1H104K Capacitors_SMD:C_0603
4 C1, C2, C3, C4 1uF WIMA MKS2C041001F00MSSD 505-MKS2C041001FMSSD Capacitors_THT:C_Rect_L7.2mm_W5.5mm_P5.00mm_FKS2_FKP2_MKS2_MKP2
2 C5, C6 1uF Taiyo Yuden GMK107BJ105KAHT 963-GMK107BJ105KAHT Capacitors_SMD:C_0603
3 C7, C8, C11 22uF Nichicon UVK1H220MDD 647-UVK1H220MDD Capacitors_THT:CP_Radial_D5.0mm_P2.00mm
1 D1 green Lite-On LTST-C190KGKT 859-LTST-C190KGKT LEDs:LED_0603
1 J1 8 pin header Molex 22-23-2081 538-22-23-2081 V5_Connectors:Molex_22_23_2081
5 Q1, Q2, Q3, Q4, Q5 BSS138 On Semiconductor BSS138L 512-BSS138L TO_SOT_Packages_SMD:SOT-23
2 Q6, Q7 SQ4282 Vishay SQ4282EY-T1_GE3 78-SQ4282EY-T1_GE3 V5_IC:SO8
1 R23 332R Vishay/Dale CRCW0603332RFKEAC 71-CRCW0603332RFKEAC Resistors_SMD:R_0603
1 R21 2K15 Vishay/Dale CRCW06032K15FKEA 71-CRCW0603-2.15K-E3 Resistors_SMD:R_0603
4 R6, R7, R10, R11 21K5 Vishay/Dale CRCW060321K5FKEA 71-CRCW0603-21.5K-E3 Resistors_SMD:R_0603
4 R17, R18, R19, R20 47K5 Vishay/Dale CRCW060347K5FKEAC 71-CRCW060347K5FKEAC Resistors_SMD:R_0603
5 R1, R2, R3, R4, R22 100K Vishay/Dale CRCW0603100KFKEAC 71-CRCW0603100KFKEAC Resistors_SMD:R_0603
4 R5, R8, R9, R12 196K Vishay/Dale CRCW0603196KFKEB 71-CRCW0603196KFKEB Resistors_SMD:R_0603
4 R13, R14, R15, R16 1M0 Vishay/Dale CRCW06031M00FKEA 71-CRCW0603-1.0M-E3 Resistors_SMD:R_0603
1 U1 78L05 Diodes Inc AS78L05ZTR-E1 621-AS78L05ZTR-E1 V5_Transistors_Diodes:TO-92_Inline_Wide_Oval
1 U2 79L05 On Semiconductor MC79L05ACPRMG 863-MC79L05ACPRMG V5_Transistors_Diodes:TO-92_Inline_Wide_Oval
2 U3, U4 LM393 Texas Instruments LM393ADR 595-LM393ADR V5_IC:SO8
2 U5, U6 TLP3906_OPTO Toshiba TLP3906(TPL,E 757-TLP3906E V5_Transistors_Diodes:Toshiba_TLP3906_opto

In the attached file, remove the .asc extension and open as an Excel file.

 

[randytsuch]

I might have a few TLP3906’s left if you can’t find them. Parts are a total nightmare to source lately.

So I screwed around too much, was figuring out what I needed for the other projects, and TLP's are not OOS.

Any chance to get a few for my project?

Thanks
Randy

 

[xrk971]

Sure, I have a few (I got them from Jhofland in fact as they are totally out for a while). How many do you need?

 

[randytsuch]

Sure, I have a few (I got them from Jhofland in fact as they are totally out for a while). How many do you need?

Sent a PM to not pollute this thread anymore. Randy