Borbely EB-1198/116 Preamp
#1 Borbely EB-1198/116 Preamp
I think I picked up the bargain of the year!
I saw a pre-amp listed on DIY Audio - the guy said it was an Erno Borbely design but didn't know which one. I studied the photographs and had a hunch that it was the 1198/116 All-FET design so, as it was listed for a very good price, I took the plunge. It arrived this week and my hunch was correct.
https://audioxpress.com/article/The-All-FET-Line-Amp
Although I bought the pre-amp with its chassis, unfortunately the guy had dismantled it and cut all the in/out wiring so this afternoon I've hooked up some input/output connections and checked it out - all good. I've just spent a couple of hours listening with it driving the Sony VFET follower I recently built. The pre-amp is phenomenally good, so much resolution and delicacy, it is a delight with the VFET, even just using my cheap Ariston bench speakers.
This pre-amp is an absolute keeper and I'll work on rehousing it and making a few improvements - It has, probably starting with bypassing all the relay input/mute stuff (I only need one input) and replacing the Alps Blue pot with a better volume control, maybe with a Slagle autoformer I've not used.
I saw a pre-amp listed on DIY Audio - the guy said it was an Erno Borbely design but didn't know which one. I studied the photographs and had a hunch that it was the 1198/116 All-FET design so, as it was listed for a very good price, I took the plunge. It arrived this week and my hunch was correct.
https://audioxpress.com/article/The-All-FET-Line-Amp
Although I bought the pre-amp with its chassis, unfortunately the guy had dismantled it and cut all the in/out wiring so this afternoon I've hooked up some input/output connections and checked it out - all good. I've just spent a couple of hours listening with it driving the Sony VFET follower I recently built. The pre-amp is phenomenally good, so much resolution and delicacy, it is a delight with the VFET, even just using my cheap Ariston bench speakers.
This pre-amp is an absolute keeper and I'll work on rehousing it and making a few improvements - It has, probably starting with bypassing all the relay input/mute stuff (I only need one input) and replacing the Alps Blue pot with a better volume control, maybe with a Slagle autoformer I've not used.
Sorry, I couldn't resist!
#2 Re: Borbely EB-1198/116 Preamp
I took the plunge and cut down the pre-amp PCB to remove all the input switching and Alps volume pot - it will be a single input build with a better quality volume control and no remote control. I'm leaning towards using my Slagle autoformer attenuator.
Sorry, I couldn't resist!
#3 Re: Borbely EB-1198/116 Preamp
So a bit of a change in that I've decided to keep the Slagle autoformer for it's original VFET preamp project and I've ordered an Academy Audio Muses volume control board to use with the Borbely project. The Academy Audio purchase includes a power supply similar to Jan Didden's 'Silent Switcher' - 5V in for +/-14V out. To supply the 5V I'm repurposing the power supply on the preamp board that was used for the input relays, replacing the 12V transformer and 7812 with 6V and 7805 items.
https://www.academyaudio.com/product-pa ... -low-noise
https://www.academyaudio.com/product-pa ... -low-noise
Sorry, I couldn't resist!
#4 Re: Borbely EB-1198/116 Preamp
I've been hacking the Borbely pre-amp PCB today, preparing to install it in a chassis and hook-up the Academy Audio Muses volume control module.
The components on the right and the small transformer are now a floating 5V supply that will power the Academy Audio switcher supply (5V in, +/-14V out) - it's floating because the switcher has an isolated grounding arrangement.
Having discarded all the input switching relays and powered Alps blue volume control, I've had to connect some of the hookup wires to PCB tracks that I've scraped the solder resist from, so I've drilled some holes and used cable ties to provide some strain relief, lest I accidentally peel the tracks off the board.
Waiting for a chassis to be delivered from Aliexpress now.
The components on the right and the small transformer are now a floating 5V supply that will power the Academy Audio switcher supply (5V in, +/-14V out) - it's floating because the switcher has an isolated grounding arrangement.
Having discarded all the input switching relays and powered Alps blue volume control, I've had to connect some of the hookup wires to PCB tracks that I've scraped the solder resist from, so I've drilled some holes and used cable ties to provide some strain relief, lest I accidentally peel the tracks off the board.
Waiting for a chassis to be delivered from Aliexpress now.
Sorry, I couldn't resist!
#5 Re: Borbely EB-1198/116 Preamp
I've received the preamp chassis from AliExpress and have started work on it. I've started with the front panel for the Muses volume control module.
Step 1 - Make the opening in the front panel
Step 2 - Insert the 3D printed bezel
Step 3 - Install the Muses Volume control module and test.
Step 1 - Make the opening in the front panel
Step 2 - Insert the 3D printed bezel
Step 3 - Install the Muses Volume control module and test.
Sorry, I couldn't resist!
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- Thermionic Monk Status
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#6 Re: Borbely EB-1198/116 Preamp
Impressive Ray, looks like a commercial unit.
I can't remember, did you use Front Panel Express to 3D print the front cover?
I can't remember, did you use Front Panel Express to 3D print the front cover?
#7 Re: Borbely EB-1198/116 Preamp
Cheers Simon. I did most of it in front panel designer then exported it to .stp format and tweaked it in Fusion 360. I got it 3D printed at JCB, very reasonable cost.
Sorry, I couldn't resist!
- pre65
- Amstrad Tower of Power
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#9 Re: Borbely EB-1198/116 Preamp
It should have been yellow then.
The only thing necessary for the triumph of evil is for good men to do nothing.
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
Edmund Burke
G-Popz THE easy listening connoisseur. (Philip)
#11 Re: Borbely EB-1198/116 Preamp
Borbely preamp is coming together nicely.
Sorry, I couldn't resist!
#12 Re: Borbely EB-1198/116 Preamp
I just need to install the input/output RCAs now.
Sorry, I couldn't resist!