FH9HVX - Budget Conscious 100w Class AB for Lean Times

[legis31]

Thanks guys!

Coincidentally I was on the All Electronics site looking at the 4 pin harnesses when Pinkfloyd4ever's post came up! Small world!

 

[Vunce]

Those were the crimps “only” to make your own wiring harnesses.
I use this silicone jacket wire for internal hookup, super flexible, comes in many different AWG and colors. The 22AWG fits the Molex KK crimps and housings perfectly.

BNTECHGO 22 Gauge Silicone Wire Kit Red Black White Blue and Green Each 30ft 22 AWG Stranded Wire https://www.amazon.com/dp/B06Y5CXVDS/ref=cm_sw_r_cp_api_glc_fabc_rqc0FbP7ZPQPZ

 

[thirdicomplex]

Low power version

Would the circuit still perform well as a low power amp? Say with a 27-0-27 200VA transformer. I'm planning on using the FH9HVX as a tweeter or midrange amp in an active setup

 

[xrk971]

Yes, I have used it at +/-35v rails and it works great there as designed. This is a 50w amp at that voltage so still quite bit of power. I would not call that a low wattage amp.

 

[wtnh]

Those were the crimps “only” to make your own wiring harnesses.
I use this silicone jacket wire for internal hookup, super flexible, comes in many different AWG and colors. The 22AWG fits the Molex KK crimps and housings perfectly.

BNTECHGO 22 Gauge Silicone Wire Kit Red Black White Blue and Green Each 30ft 22 AWG Stranded Wire https://www.amazon.com/dp/B06Y5CXVDS/ref=cm_sw_r_cp_api_glc_fabc_rqc0FbP7ZPQPZ

And if you don't want to spring for an actual crimping tool, I have had good luck crimping the Molex pins with a small needle-nose piers, then soldering the crimp. It is a bit tedious, but I am too cheap to buy yet another tool

 

[xrk971]

I used to do that but trust me, the $20 for the tool is totally worth it as the connector quality is superior and it takes 1 minute vs 5min. Also, the solder can wick into the spring loaded clip and ruin the action. If you do DIY enough, and I think you do, one of the best things to get. I have a whole drawer full of crimper tools but the Molex KK and JST ones are the most used. Also the big ones for the spades and loop terminals.

Here is the one for Molex KK
IWISS Open Barrel Terminal Crimper Plier Tool for Molex Style DELPHI AMP TYCO Deutsch Terminals Crimper Open Barrel 24-14 AWG https://www.amazon.com/dp/B07476C1LD/ref=cm_sw_r_cp_api_glc_fabc_C860FbAQSCZ97
Here is JST one:
IWISS SN-01BM Ratchet Crimper AWG28-20 for XH2.54/3.96,PH2.0,PX,JST,Molex Terminal https://www.amazon.com/dp/B019ARWWFY/ref=cm_sw_r_cp_api_glc_fabc_9960FbAM3BCKT?_encoding=UTF8&psc=1

 

[454Casull]

The conductor cross-sectional view they show for the 1424A crimper is... horrible. I don't know why they thought that would be impressive. Looking past the surface finish, the lack of strand deformation and even air gaps in the crimp zone is very telling.

 

[xrk971]

For a non soldered joint, I think that looks quite good. It’s a wire-EDM cut cross sectional view. The wire-EDM process puts a rough finish on the cut. Do you have photos of what you expect it to look like if it was correctly done?

 

[jorgovanko]

What is the minimal voltage for 100pF compensation caps if the PSU is +-45V?

 

[xrk971]

Silver mica will generally be 250v rated minimum. NP0/C0G MLCC’s need to be 100v rated.

 

[wtnh]

I used to do that but trust me, the $20 for the tool is totally worth it as the connector quality is superior and it takes 1 minute vs 5min. Also, the solder can wick into the spring loaded clip and ruin the action. If you do DIY enough, and I think you do, one of the best things to get. I have a whole drawer full of crimper tools but the Molex KK and JST ones are the most used. Also the big ones for the spades and loop terminals.

Here is the one for Molex KK
IWISS Open Barrel Terminal Crimper Plier Tool for Molex Style DELPHI AMP TYCO Deutsch Terminals Crimper Open Barrel 24-14 AWG https://www.amazon.com/dp/B07476C1LD/ref=cm_sw_r_cp_api_glc_fabc_C860FbAQSCZ97
Here is JST one:
IWISS SN-01BM Ratchet Crimper AWG28-20 for XH2.54/3.96,PH2.0,PX,JST,Molex Terminal https://www.amazon.com/dp/B019ARWWFY/ref=cm_sw_r_cp_api_glc_fabc_9960FbAM3BCKT?_encoding=UTF8&psc=1

Did not realize you can get a crimper that works with the Molex stuff so cheap - $16.00 - thanks for the pointer. I had looked at the "real" Molex tool and had sticker shock

This discovery comes after I just finished a preamp project with about 100 Molex pins to crimp!!

 

[xrk971]

Real branded crimpers from Molex or AMP are for manufacturing factories I suppose. Circa $300 to $500. Crazy prices I know.

 

[zei]

So I guess this supply is a tad to much for this amp?
Output Voltage: 2x85Vdc
Max. Output power: 3600W

Hypex Electronics B.V.

/JZ

 

[zman01]

JZ,

You are correct, that one would be too high.

You already have that one, or planning to get a power supply?

 

[zei]

zman01 I have this supply already. But I,ll try to find something good with close to 53V rails.

/JZ

 

[454Casull]

For a non soldered joint, I think that looks quite good. It’s a wire-EDM cut cross sectional view. The wire-EDM process puts a rough finish on the cut. Do you have photos of what you expect it to look like if it was correctly done?

https://www.te.com/commerce/DocumentDelivery/DDEController?Action=srchrtrv&DocNm=402-1002&DocType=SS

 

[xrk971]

Thanks for that link, Casull! Those are nice crimps - basically, the wire and crimp terminal are cold-welded together under the extreme pressure.

 

[xrk971]

Hey folks, free Xmas amp TDA7293 PCB giveaway here.
Xmas Amp - Dibya's TDA7293 by Jhofland

Happy Holidays!

 

[xrk971]

For those of you planning on using the All Cee’s PSU board, we found a small error on X116.
All Cee's PSU for Class AB Amp

It’s easily fixable with a solder bridge or simply use R116 pads next to it.

 

[454Casull]

Thanks for that link, Casull! Those are nice crimps - basically, the wire and crimp terminal are cold-welded together under the extreme pressure.

Yep. Completely gas-tight, and with minimal added resistance from the wire-connector interface.