MonAmour, our new premium 2A3 monoblocks kit

Doc B. · 11839

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Offline Paul Birkeland

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Reply #30 on: January 09, 2020, 10:02:03 AM
Has there been any discussion about a future 2A3 based preamp to match the MonAmour or would you just stick with the BeePre?
You can also plug 6A3s into a BeePre or 6B4Gs with an adapter.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Doc B.

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Reply #31 on: January 09, 2020, 03:06:22 PM
We shipped the first half of the MonAmour orders in our queue this afternoon. We're just awaiting some resistors that should be here early next week to finish packing the second half of the orders.

Dan "Doc B." Schmalle
President For Life
Bottlehead Corp.


Offline triode

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Reply #32 on: January 09, 2020, 08:56:54 PM
Hi Doc/Paul,

I received the notification of the shipment. Very excited
Has the manual ready? Can I download it?

Thanks



Offline fullheadofnothing

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Reply #33 on: January 10, 2020, 06:22:54 AM
The manual was released a week or so ago. At that time I emailed all purchasers of the kit directly with instructions on how to download. I just resent the email to the only person who has not downloaded the manual now.
« Last Edit: January 10, 2020, 06:33:32 AM by fullheadofnothing »

Joshua Harris

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Offline triode

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Reply #34 on: January 10, 2020, 08:29:20 AM
Hi Joshua

I have not receive any email instruction on how to download the manual.
But I did receive invoice (no 16863) and tracking notification

Could  you please check?

Thanks



Offline fullheadofnothing

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Reply #35 on: January 10, 2020, 01:28:06 PM
From posting your invoice number I can tell that I have correctly identified you. I sent both the email a week ago and the one from this morning to the hotmail address that you provided with that order. Since you received the tracking and order confirmations, that means that the address is correct, so perhaps my messages were caught by your spam filter?
I have now resent the message through the shopping cart system. Hopefully that will go through.

Joshua Harris

I Write the Manuals That Make The Whole World Sing
Kit Packer Emeritus


Offline triode

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Reply #36 on: January 10, 2020, 02:12:01 PM
Got it now.

Thank you very much Josh



Offline triode

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Reply #37 on: January 12, 2020, 07:09:53 PM
Hi Josh/Paul,

I've been studying the manual as build preparation and try to understand the steps/circuits.
I just have one thing that I don't understand : on page 62, one of the step is to connect red wire from A6 to Kreg on A side of circuit board. Isn't the A6 the anode of the tubes that should be connected to OB instead? I think Kreg should be connected to Cathode A8?

Thanks



Offline Paul Birkeland

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Reply #38 on: January 13, 2020, 04:40:11 AM
You are correct, we will get that revised.  Thankfully the photo shows the correct procedure and there's no wire poking up from A6 at that juncture.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline triode

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Reply #39 on: February 21, 2020, 10:45:11 PM
Hi,

MonAmour build finished!
I decided not to use the power trans cover and showing painted transformer bell instead.
There is some faint hiss that I can hear 2 meter away from the speaker. I suspect its due to TL431 in the cathode. The Stereomour also has the same hiss until I change to simple cathode resistor. Note that my tweeter is very sensitive (Fostex T90A, 106dB/W/m). There is no hiss if I connect the amp to Harbeth P3ES (LS3/5 variant)

The sound : its very clean sounding. Treble is very nice and extended.
Using Sovtek, I thought the mid is slightly harsh at the beginning (relatively, compare to Paramount, not harsh at all in the absolute term). After some break in and switching to JJ 2A3-40 it smooth out and very clean sounding. I think its less forward compare to Stereomour 45.
I can't comment on bass since my speakers have active bass from 200Hz down.






Offline Paul Birkeland

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Reply #40 on: February 22, 2020, 05:55:01 AM
Excellent work!  If you want to change to resistor bias at the input, a 930 ohm resistor should set you up nicely.  The gain will drop a little in the process, but with tweeters that sensitive, that certainly shouldn't be an issue!

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline Karl5150

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Reply #41 on: February 22, 2020, 07:54:13 AM
Amp Envy!
Triode, I like your idea of leaving the cover off. I initially liked the cover, thinking it gave the amps a more "finished" quality. Yours has the classic BH look. Good work.

Karl
Downstairs: Planar3>PH-16>Stereomour II>OB Betsy+
Upstairs: RP1>Eros/CD5004>Seductor (2x Monoblocks)>FH3
Office: Modi Uber 2/Sirius>SEX2.1.1>µFonken FF85WK + DC160 subs
BR: FiiO M6>SEX3.0.1>ScanSpeak 10F + TangBand W6 (Mono)/DT770Pro
Garage: X12 streamer>Quicksand>Minimus 77


Offline hitmanray

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Reply #42 on: February 22, 2020, 10:50:09 AM
Need some help please. When I went to complete the bias checks, both amps showed low on the meters with the toggle switch in both positions. Are these readings within acceptable tolerance or do I need to go back and check on some things?

Not sure if it makes any difference but the voltage readings during my power checks were all at the high end of the allowable tolerances.

Thanks



Offline triode

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Reply #43 on: February 22, 2020, 10:57:38 AM
Thanks Paul, Karl.

Paul, if I want to change to 930ohm resistor, should I leave the 5k and 10k trimpot in parallel (giving resistance from cathode to ground around 785-875 ohm range) or just took the whole thing out and replace by 930ohm? Maybe also put capacitor in parallel?

Completely different subject (just a thought): How to convert to 45 output tube? I would imagine we need to change the 130ohm HT dropping resistors (to 560ohm?), add filament dropping resistor (by 0.47ohm?) and change the 270ohm cathode resistor (to 750ohm?)

Hitmanray,
That what the meter shown in mine too. I think its OK. When I measure the voltage and resistance an do the calculation, its actually biased on 53mA and 64mA. It,s just the meter not really accurate. You can adjust the meter a bit by turning the screwdriver slot in the bottom of the meter

Thanks



Offline hitmanray

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Reply #44 on: February 22, 2020, 11:01:28 AM
Awesome, thanks Triode.

I figured it would be OK, but so far everything has been right on the money in line with the awesome instructions and I figured there would be a tolerance stated if allowable.

Will keep pressing on unless one of the gurus jumps in and tells me otherwise.