Help needed to identify a Pro-ject Phono Box to source the PSU

[ManniX]

Greetings,
Would need help to identify a Pro-ject Phono Box, the power supply has been lost and I need to buy a new one.
It's not listed anywhere on the Pro-ject website neither I could find it Googling around.
Must be a very early model, seems to be hand made.
Any idea?

Thanks!

 

[Esprit]

I found this photo, see if it can be useful to you:

 

[Esprit]

ChatGPT:
Certainly! Here's a complete English version of the information regarding your Pro-Ject Phono Box and compatible power supplies:

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Compatible Power Supplies for Pro-Ject Phono Box (First Generation)​

Your unit in the photo is the original Pro-Ject Phono Box (not the newer models like Phono Box S or DS), a basic MM/MC phono preamp. It requires a 18V AC (not DC) power supply with at least 250 mA output. The original adapter is labeled “AC/AC 18V 250mA.”

---

Recommended Replacement Power Adapters​

1. MyVolts 18V AC Adapter – EU Plug​

• Type: AC to AC (not DC)
• Output Voltage: 18V AC
• Current: 250 mA or more
• Plug: Standard EU 2-pin
• Price: Approx. €13.49
• Buy Link: Amazon.it - MyVolts 18V AC Adapter

2. Generic Replacement Adapter (Fruugo)​

• Type: AC to AC
• Output Voltage: 18V AC
• Current: 250 mA
• Plug: EU compatible
• Price: ~€15.95 + shipping (€13.49)
• Buy Link: Fruugo.it - 18V Replacement AC Adapter

Important Note: Make absolutely sure the adapter is AC to AC, not AC to DC. Using a DC adapter may damage your phono stage.

---

Optional Upgrade – Pro-Ject Power Box S3 Phono​

If you're looking for a cleaner power supply for better performance and reduced noise:

• Type: Linear power supply
• Outputs:
  • 18V for phono stages
  • 15V for Pro-Ject turntables
• Key Features:
  • Very stable, filtered voltage
  • Low ESR capacitors
  • Aluminum chassis to reduce interference
• Price: ~€169
• Buy Link: AudioImpact.it – Power Box S3 Phono

---

Summary Table​

Product	Type	Voltage	Current	Price	Link
MyVolts 18V Adapter	AC/AC	18V	250 mA	~€13.49	Amazon
Generic 18V Adapter	AC/AC	18V	250 mA	~€29.44	Fruugo
Pro-Ject Power Box S3	Linear PSU	18V / 15V	1000 mA	~€169	AudioImpact

---

Let me know if you'd like help choosing the best one based on where you're located or your setup!

 

[Roland68]

Greetings,
Would need help to identify a Pro-ject Phono Box, the power supply has been lost and I need to buy a new one.
It's not listed anywhere on the Pro-ject website neither I could find it Googling around.
Must be a very early model, seems to be hand made.
Any idea?

View attachment 447566

View attachment 447567

View attachment 447568

Thanks!

For this, you need a transformer (AC/AC) with approximately 12 or 16 volts and 200 mA.

No DC power supply, it won't work with that.

 

[Esprit]

Power Supply (from photo):

• Type: AC/AC Adapter ( not DC)
• Model: MKA-160200GS
• Input: 230V ~ 50Hz, 100mA
• Output: 16V ~ (AC), 200mA
• Made in: Taiwan

This is a 16V AC output transformer, not a DC switching power supply, which is very important: using a DC supply could damage the Pro-Ject Phono Box.

Compatible Power Supplies​

1. Pro-Ject 16V / 500mA AC Power Supply​

• Type: AC/AC
• Output: 16V AC, 500mA
• Compatibility: Suitable for Pro-Ject Phono Box, Phono Box II, Phono Box USB, and various Pro-Ject turntables.
• Price: €21.95
• Availability: VinylVinyl.nl

2. Pro-Ject Replacement PSU Power Supply​

• Type: AC/AC
• Output: 16V AC, 500mA
• Compatibility: Designed for Pro-Ject turntables and phono electronics.
• Price: £21.99
• Availability: Analogue Seduction

3. Genuine Pro-Ject 16V / 500mA AC Power Supply​

• Type: AC/AC
• Output: 16V AC, 500mA
• Compatibility: Compatible with Pro-Ject Phono Box, Phono Box II, Phono Box USB, and other models.
• Price: Approximately $30
• Availability: eBay

---

Important Notes​

• AC/AC Requirement: Ensure that the replacement power supply provides AC output. Using a DC output adapter can damage your Pro-Ject Phono Box.
• Current Rating: While your original adapter is rated at 200mA, using a power supply with a higher current rating (e.g., 500mA) is acceptable. The device will only draw the current it needs.
• Plug Compatibility: Verify that the plug type and size match your device's input to ensure proper connection.

 

[Roland68]

ChatGPT:
Certainly! Here's a complete English version of the information regarding your Pro-Ject Phono Box and compatible power supplies:

---

Compatible Power Supplies for Pro-Ject Phono Box (First Generation)​

Your unit in the photo is the original Pro-Ject Phono Box (not the newer models like Phono Box S or DS), a basic MM/MC phono preamp. It requires a 18V AC (not DC) power supply with at least 250 mA output. The original adapter is labeled “AC/AC 18V 250mA.”

---

Recommended Replacement Power Adapters​

1. MyVolts 18V AC Adapter – EU Plug​

• Type: AC to AC (not DC)
• Output Voltage: 18V AC
• Current: 250 mA or more
• Plug: Standard EU 2-pin
• Price: Approx. €13.49
• Buy Link: Amazon.it - MyVolts 18V AC Adapter

2. Generic Replacement Adapter (Fruugo)​

• Type: AC to AC
• Output Voltage: 18V AC
• Current: 250 mA
• Plug: EU compatible
• Price: ~€15.95 + shipping (€13.49)
• Buy Link: Fruugo.it - 18V Replacement AC Adapter

---

Optional Upgrade – Pro-Ject Power Box S3 Phono​

If you're looking for a cleaner power supply for better performance and reduced noise:

• Type: Linear power supply
• Outputs:
  • 18V for phono stages
  • 15V for Pro-Ject turntables
• Key Features:
  • Very stable, filtered voltage
  • Low ESR capacitors
  • Aluminum chassis to reduce interference
• Price: ~€169
• Buy Link: AudioImpact.it – Power Box S3 Phono

---

Summary Table​

Product	Type	Voltage	Current	Price	Link
MyVolts 18V Adapter	AC/AC	18V	250 mA	~€13.49	Amazon
Generic 18V Adapter	AC/AC	18V	250 mA	~€29.44	Fruugo
Pro-Ject Power Box S3	Linear PSU	18V / 15V	1000 mA	~€169	AudioImpact

---

Let me know if you'd like help choosing the best one based on where you're located or your setup!

So much for the useless information from ChatGPT.

This first version of "The Phono Box" was delivered with a 16-volt AC/AC transformer, but it also worked flawlessly with a 12-volt AC/AC transformer.
Due to the small voltage regulators (TO-92) without a heat sink, I would definitely not use the 18-volt AC/AC transformer.

The voltage of the 18-volt Project Phono Box is printed on the back.

 

[ManniX]

I found this photo, see if it can be useful to you:

Thanks, it's the first image from Google image search... I kinda suspect that I have uploaded the wrong image at the time

For this, you need a transformer (AC/AC) with approximately 12 or 16 volts and 200 mA.

I'd have probably bought in a rush the first one in the picture, the 100mA I had find it...
Definitely a good idea to ask!

This first version of "The Phono Box" was delivered with a 16-volt AC/AC transformer, but it also worked flawlessly with a 12-volt AC/AC transformer.
Due to the small voltage regulators (TO-92) without a heat sink, I would definitely not use the 18-volt AC/AC transformer.

Absolutely valuable info, thanks a lot will look for a 16V

 

[lini]

Absolutely valuable info, thanks a lot will look for a 16V

15 V(AC) will do, too.

I.e., basically the power supply just needs to deliver a sufficiently high peak voltage (= in theory the nominal voltage times the square root of two), so that this peak voltage (with which the elcaps after the rectification diodes will be charged) minus ca. 0.7 V (= voltage drop at each of the two rectification diodes) is at least ca. 2.5 to 3 V higher than the nominal voltage of the voltage regulators (those little three-legged ICs between the ceramic disc capacitors; most likely a 7815 for the positive and a 7915 for the negative rail), so that these can properly do their job.

So in theory, 12 V(AC) nominal would appear somewhat marginal (12 V x 2^0.5 - 0.7 V = not quite 16.3 V). However, in practice you'll nowadays typically find power supply models with higher than necessary current capability, and the nominal output voltage generally refers to the nominal current capability (e.g. 500 mA), while the idle voltage and also the actual output voltage in combination with a load, that draws quite a good bit less power, will be a good bit higher, so that even for example a model 12 V(AC) and 500mA nominal would most likely still work fine.

Nevertheless I'd rather suggest to get a 15 V(AC) / 500 mA model, not only to exclude insufficient output voltage, but also because these thingies also work nicely as replacement power supplies for various classic Thorens turntables (like for example the TD280s and TD316/318/320s), so you might actually want to buy two, in case you'd happen to have such a Thorens (*). See for example there for a priceworthy source: https://www.ebay.de/itm/152995331723/

Greetings from Munich!

Manfred / lini


*) For use with such a Thorens you might want to replace the standard 5.5 x 2.1 mm barrel plug with a DIN 45323 compliant plug like for example the Lumberg NES 1 for a more secure fit, though - especially if the standard barrel connector would happen to have a rather short barrel length.

 

[ManniX]

Thanks @lini, very helpful!
And @Roland68 and @Esprit as well of course.

Will ask again for your help when I'm back in Frankfurt A.M., there's a little history behind this box.

This Phono Box was gifted to me by a friend who I helped with moving his stuff from one house to another.
He's an expat like me but he had to leave here in Rome his HiFi since he moved to Paris, where the flats are just very very "petite".
It's broken and only one channel works (that's what he remembers about it), so it's a small repair project for fun.
He has a Rega turntable and pre-amp, this one was being thrown in the trash and I couldn't let it go

If I can fix it I'll probably use it with a Technics SL-1200 (not the Mk II, the very first model) that I have here in Rome.
I had just bought a couple of weeks ago a Fosi X5 for it.
Which unfortunately I couldn't really appreciate since the turntable was stored in a shelf for almost 20 years and it's a total mess.
Will need to service it and if I can't revive it bring it to a specialist.

I was planning to buy another X5 for my daily driver turntable in Frankfurt which is a Technics SL-3300.
But if I can fix the Pro-ject phono box I'll use it in Rome and move the X5 to Frankfurt.
I guess the X5 would blow away the Pro-ject but realistically I will not use the SL-1200 in Rome more than a few hours per year...

So I'll come back for help when I'll start investigating what's wrong with the phono box.

Greetings from Rome!