NAD 6300

[overmodulated]

No idea on circuitry, but I would just leave the lid off if it runs that hot.

Maybe run the 6100 for a long time to determine WHERE it is throwing a lot of heat and then make holes/slots there. Then corresponding ones in the bottom plate to allow convection. I wouldn't run a fan... it shouldn't be needed.

That sounds like a good idea thanks. I know some of the guys are adding heat sinks to the power supply of this deck, and that may be something to do in the future.

 

[Elite-ist]

My NAD 6300 has never been serviced since I've owned it. So, after five years of being parked in a display case in the upstairs living room, today, I pulled it out of the cabinet for a demo session.

I, already, had been using my NAD 616 dual-well deck and NAD 3020 integrated amplifier for the past few days. Also, I connected my Beogram 4002 linear-tracker turntable into the system. Looking to retip or replace the cartridge on the 4002. Too bad the Bang & Olufsen cartridges are so expensive.






And a cell phone video. That's Chris' @Chris Cables mix tape playing in the NAD 6300.

Nando.

 

[mr_rye89]

I never knew NAD built a double cassette deck. I had an early NAD 3020 that I hot-rodded and sold for a pretty penny a few years back.....

 

[overmodulated]

My NAD 6300 has never been serviced since I've owned it. So, after five years of being parked in a display case in the upstairs living room, today, I pulled it out of the cabinet for a demo session.

I, already, had been using my NAD 616 dual-well deck and NAD 3020 integrated amplifier for the past few days. Also, I connected my Beogram 4002 linear-tracker turntable into the system. Looking to retip or replace the cartridge on the 4002. Too bad the Bang & Olufsen cartridges are so expensive.

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And a cell phone video. That's Chris' @Chris Cables mix tape playing in the NAD 6300.

Nando.

everything looks great.

 

[overmodulated]

I’m not well-versed in this so bear with me, and the decks that I’ve had generate their own tone, and the bias is very easy to set.

This being said since there’s no tone generator on the 6300, and the instructions that I’ve seen save to either record music and listen to it and adjust to taste, or record white noise from in-between radio stations.

I found this online to adjust the bias, it was on a tape head thread, and all the well-known texts were on there talking about it, but one person suggested this;

“Record a 1khz tone, and adjust the record level controls so that the meters read -10db while monitoring the tape. Now generate a 10khz tone and record it. Don't touch the record level controls. Is the 10khz tone also playing at -10db? If not, adjust bias until it does”

Do you think this will work? I could get the tones easily from an app, or online and supply it through my DAC to my receiver and record.

The reason I’m saying this is I don’t hear much above 13,000 Hz anymore.

 

[J!m]

That method is to set record level, not bias current.

 

[overmodulated]

I don’t think so. The record level is set different, and that would be set to around zero to +3 or so.

there are guys that are setting the bias like this. Maybe Nando would comment. Thanks

 

[overmodulated]

This was in a thread about bias adjustment for decks that don’t have their own tones;


How to adjust the bias according to a tape heads member;

“Another way to do this adjustment is to connect your computer to your deck, and find a site that will generate sine tones. Record a 1khz tone, and adjust the record level controls so that the meters read -10db while monitoring the tape. Now generate a 10khz tone and record it. Don't touch the record level controls. Is the 10khz tone also playing at -10db? If not, adjust bias until it does. Now iterate this process 2-3 times. What you want is to come up with a bias level where the 1khz tone and the 10khz tone play back at exactly the same level”

I was just going to do through my DAC into my receiver

 

[J!m]

my Tascam has internal tones, but you set bias current and record level as two trim pots. They DO interact with each other, but you must set both, so each is registering properly. That may be the confusion.

But the procedure you documented ensures the input level is what is registered onto the tape. Changing bias current will alter that record level, and it will need to be readjusted. Back and forth until both are within spec.

That's for every deck, not just the NAD. Nature of the beast.

 

[overmodulated]

my Tascam has internal tones, but you set bias current and record level as two trim pots. They DO interact with each other, but you must set both, so each is registering properly. That may be the confusion.

But the procedure you documented ensures the input level is what is registered onto the tape. Changing bias current will alter that record level, and it will need to be readjusted. Back and forth until both are within spec.

That's for every deck, not just the NAD. Nature of the beast.

Understood

 

[overmodulated]

I am trying do the same thing that the 6300 manual says, but instead of using your ears you do it with a test run recording, i’m using a sine wave actually two of them in a test run recording.. With the first tone you bring the level up to -10, then without touching the recording level you feed your deck the next tone, and if it’s different than -10 you would adjust it with the BIAS TRIM to match it to -10 if it’s different.

Then you can set your recording level as needed.

Here’s a thread explaining things;

https://www.tapeheads.net/threads/recording-bias-adjustment-by-ear.85151/

The recording level is set after this procedure, and I’m not going to record to -10.

Anyway I was wondering if anybody has experience doing it this way? It appears quite a few of the guys on tapeheads.net use this procedure or one pretty much like it to set the bias of a tape, for decks without tone generators, or they use pink noise.

 

[Elite-ist]

I am sure that link to the bias adjustment is meant for internal adjustment on an open-reel deck (Sony TC-200) which has no user-adjustable bias control on the exterior of the deck.

Nando.

 

[Elite-ist]

@mr_rye89: Kyle, this NAD 3020 integrated amplifier is wonderful - I am glad I decided to have it repaired. It sat on a shelf for long time - like 16 years in non-working condition. It's cosmetically-challenged and it's rare for me to keep a component in that kind of condition.

Yes, the NAD 616 gets lots of accolades. I bought it at a thrift store for $15 CAD - on the same day I sold a system at a shop across the street. The system featured an NAD 6220 cassette deck, NAD 3240PE integrated amplifier and a pair of Realistic Minimus 7 speakers.

NAD amps of this vintage are reknown:

3240PE
Stereo Receiver
Date of manufacture : Sep 88 - ?
Please note that this document contains the text from the original product brochure, and some technical statements may now be out of date
According to a long-established industry custom, the highest-quality parts and most highly refined designs are found only in separate audio components - in preamps, power amplifiers, and tuners. Integrated amplifiers usually arc made to a less exalted standard, while all-in-one stereo receivers are regarded as mid-fi products suitable only for first-time buyers.
But not at NAD. Whether you choose the flexibility of separates, the convenience of an integrated amplifier, or the economy of a receiver, all NAD audio components share a single design philosophy. Often the very same highly-refined circuits are used in both separates and combination products. For example, the NAD 3240PE integrated amplifier contains the best-buy 2240PE power amplifier, combined with preamplifier and control circuits similar to those in the 1240PE preamp. The 3240PE costs only a little more than other “medium-power” amplifiers, but its no-frills exterior conceals a powerhouse of advanced design. Its high-current output stage delivers full output to loudspeakers of any impedance (even as low as 2 ohms), producing peak currents up to 25 amperes for precise dynamic control of speaker voice-coil motion.
The 3240PE is conservatively rated to deliver 40 watts of continuous power per channel into either 8 or 4 ohms, but i t s Power Envelope design yields extraordinary reserves of tone-burst power for music. With +6 dB of dynamic headroom, the 3240PE delivers over 160 watts per channel at 8 ohms (200 watts/ channel at 4 or 2 ohms) for the high-level transient peaks in today’s wide-range recordings. And the 3240PE puts out 100 watts per channel of clean, clear power for the full 200-millisecond duration of the notes and chords of a grand piano, symphony orchestra, or large jazz band.
The preamplifier section of the 3240PE is based on the 1240PE’s outstandingly quiet, wide-range phono stage. It features precise RIAA equalisation, very low noise, and ample headroom to accommodate the highest-level peaks without distortion. The dynamic range o f the phono preamp circuit exceeds 100 dB. Bass EQ provides solid, subwoofer-like reinforcement of the low bass, extending the useful response of most loudspeakers an extra half-octave lower. It strengthens the fundamental tones of pipe organ, bass drum, and synthesizer with no boomy mid bass emphasis. The Bass EQ circuit rolls off sharply below 30 Hz to avoid woofer damage and minimise unwanted cone-flapping caused by note-musical signals such as LP disc warps.
NAD’s unusually useful tone controls provide musically effective corrections at very low and high frequencies without altering the amplifier’s fundamentally neutral midrange sound.
Preamp Out and Main In jacks make it easy for you to upgrade your audio system by adding an equaliser, a surround-sound processor, an electronic crossover, or another power amplifier.
NAD amplifiers are praised around the world for their advanced engineering, modest pricing, uncomplicated controls, and state-of-the-art sonic performance. For accuracy, freedom from noise and distortion, and supremely musical sound quality, the 3240PE is unmatched in value. It has power reserves to drive the finest loudspeakers with ease, and it will do justice to the finest recordings.


Nando.

 

[overmodulated]

I am sure that link to the bias adjustment is meant for internal adjustment on an open-reel deck (Sony TC-200) which has no user-adjustable bias control on the exterior of the deck.

Nando

I’ll have to go back and read it more thoroughly, but I’m pretty sure it’s about adjusting the bias before recording.

Edit;
It appears you’re right Nando, they were talking about the internal bias adjustment. I’m still looking for a more technical way to adjust the bias on the 6300, I’ll know more once I receive it but doing it by ear does not seem optimal to me.

 

[J!m]

Ear? no.

"In God we trust. Everyone else must have lots of data."

 

[overmodulated]

Ear? no.

"In God we trust. Everyone else must have lots of data."

I do agree with that

 

[Chris Cables]

I briefly owned a NAD 6340 which is the NAD deck many people rave about, especially that cranky old basturd Lucky over on TH.
When I bought it the owner already warned me it had a few caveats, such as not being able to play anything for more than 30 seconds. Meh, sounds like an easy enough fix, or so I thought....
Pulling that thing apart was infinitely more difficult than working out how to unclip my gf's bra back when I was a sweaty-handed, clumsy 16yr old. I thought there would never be a more challenging, anxiety-inducing mind-fk than that....until I came face-to-face with the NAD 6340.

Integral parts of that thing are held together with resin glue ffs!
Where you can expect to just unscrew and remove the transports of most decks you need a hot-air gun and the patience of a saint when it comes to NAD decks.
It eventually beat me, which was a severe disappointment and a personal letdown, but I managed to trade it for a Nak AV-8 amplifier with a noisy internal fan (which I could fix).
Silver linings. -.-

 

[overmodulated]

I’m hoping it doesn’t need too much service, I know I can get to the back tension belt, but it’s supposed to be OK so we will see

 

[overmodulated]

Not sure where to go if I need belts for this. Looks like Marrs communications is no longer in business.

 

[overmodulated]

Here is a start, if you don't plan to use additional equipment such as a tone generator, external meter, etc.


1) Load the selected cassette into the recorder and fast-wind the tape forward for a few seconds to get past the blank leader tape at the beginning.

2) Set the Play Trim control to "0" (the detented position at the middle of it's range).

3) Set the Tape Selector to match the type of tape.

4) Set the Dolby NR switch to "C" and switch the MPX filter on. (Even though you may be planning to make a recording with Dolby B-type NR, it is best to use Dolby C-type NR while adjusting bias because it enhances the audibility of any response errors caused by over- or under-biasing.)

5) Set the Bias fine-tuning control to 0 (i.e. to the detented position at the center of it's range), unless you have reason to prefer a different trial setting.

6) Record a brief sample of music at low recording levels (approx. -15 dB). For best results the music should have obvious high-frequency content. A convenient alternative, especially when the most accurate results are desired, is to record interstation hiss from an FM tuner (with it's muting off) at a level of about -20 dB.

7) Using the INPUT MONITOR button, compare the tonal balance of the recording versus that of the input signal.

8) If the recording sounds duller than the original sound, raise the setting of the Bias fine-adjust control (move it toward the + symbol) to obtain brighter highs.

On the other hand, if the trial recording sounds bright, edgy, or distorted, reduce the setting of the Bias fine adjust control (move it toward the - symbol) to obtain smoother highs.

9) With metal-particle tapes (Type IV), you will find that the effect of bias change is relatively subtle, and you may have to move the Bias fine-tuning control all the way to the end of it's range to produce an audible change in tonal balance. But with normal tapes (Type I) a modest change in bias usually produces an obvious change in tone quality.

10) After you have discovered the Bias setting that yields the best results with a particular brand and type of tape, write it down (perhaps on the cassette label). then the next time you make a recording using the same brand and type of tape, you can easily re-set the Bias control to the optimum position. If you use a single brand of tape regularly, it will be convenient to leave the Bias fine-tuning control at the optimum setting for that tape. But if you record on a variety of tapes, you may want to compile a list of the optimum bias settings as you discover them. and post them on a card located near the recorder for convenient reference.

11) Remember, the Bias fine-tuning control affects tapes only while the recording is being made. It cannot be used to improve the quality of tapes after they are recorded.

Additionally, don't push peak recording input levels beyond lighting the first amber on the display.

Nando.

Nando, do you always use Dolby C when making your recordings with the 6300? It appears that the manual says to use it always while recording. I really don’t use noise reduction, and on my Z 9100 it’s not really necessary, a little bit of hiss doesn’t bother me.

Have you made recordings on the 6300 without Dolby engaged? If so I’m wondering what you thought of the sound.

I’ve always found it if you record with Dolby and then you must use it during playback.

Thanks.